VMware vSphere 6.7 UI Tomcat STIG
VMware vSphere 6.7 UI Tomcat Security Technical Implementation Guide. Version v1 r2, released Feb. 8, 2022.
VCUI-67-000012: vSphere UI must have mappings set for Java servlet pages.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/web.xml | sed 's/xmlns=".*"//g' | xmllint --xpath '/web-app/servlet-mapping/servlet-name[text()="jsp"]/parent::servlet-mapping' - Expected result: <servlet-mapping> <servlet-name>jsp</servlet-name> <url-pattern>*.jsp</url-pattern> <url-pattern>*.jspx</url-pattern> </servlet-mapping> If the jsp and jspx file url-patterns are not configured as in the expected result, this is a finding.
Discussion
Resource mapping is the process of tying a particular file type to a process in the web server that can serve that type of file to a requesting client and identify which file types are not to be delivered to a client. By not specifying which files can and cannot be served to a user, the web server could deliver to a user web server configuration files, log files, password files, etc. As Tomcat is a Java-based web server, the main file extension used is *.jsp. This check ensures that the *.jsp and *.jspx file types has been properly mapped to servlets.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Navigate to and locate the mapping for the JSP servlet. It is the <servlet-mapping> node that contains <servlet-name>jsp</servlet-name>. Configure the <servlet-mapping> node to look like the code snippet below: <!-- The mappings for the JSP servlet --> <servlet-mapping> <servlet-name>jsp</servlet-name> <url-pattern>*.jsp</url-pattern> <url-pattern>*.jspx</url-pattern> </servlet-mapping>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000007: vSphere UI log files must only be accessible by privileged users.
At the command prompt, execute the following command: # find /storage/log/vmware/vsphere-ui/logs/ -xdev -type f -a '(' -not -perm 600 -o -not -user vsphere-ui ')' -exec ls -ld {} \; If any files are returned, this is a finding.
Discussion
Log data is essential in the investigation of events. If log data were to become compromised, competent forensic analysis and discovery of the true source of potentially malicious system activity would be difficult, if not impossible, to achieve. In addition, access to log records provides information an attacker could potentially use to their advantage since each event record might contain communication ports, protocols, services, trust relationships, user names, etc. The vSphere UI restricts all access to log file by default, but this configuration must be verified. Satisfies: SRG-APP-000118-WSR-000068, SRG-APP-000119-WSR-000069, SRG-APP-000120-WSR-000070
Fix
At the command prompt, execute the following commands: # chmod 600 /storage/log/vmware/vsphere-ui/logs/<file> # chown vsphere-ui:users /storage/log/vmware/vsphere-ui/logs/<file> Note: Substitute <file> with the listed file.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000022: vSphere UI must be configured to hide the server version.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@server' - Expected result: server="Anonymous" If the output does not match the expected result, this is a finding.
Discussion
Web servers will often display error messages to client users with enough information to aid in the debugging of the error. The information given back in error messages may display the web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage. This information could be used by an attacker to blueprint what type of attacks might be successful. Therefore, vSphere UI must be configured to hide the server version at all times.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to each of the <Connector> nodes. Configure each <Connector> node with 'server="Anonymous"'.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000020: vSphere UI must set the welcome-file node to a default web page.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/web.xml | sed 's/xmlns=".*"//g' | xmllint --xpath '/web-app/welcome-file-list' - Expected result: <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> </welcome-file-list> If the output of the command does not match the expected result, this is a finding.
Discussion
Enumeration techniques, such as URL parameter manipulation, rely on being able to obtain information about the web server's directory structure by locating directories without default pages. In this scenario, the web server will display to the user a listing of the files in the directory being accessed. By having a default hosted application web page, the anonymous web user will not obtain directory browsing information or an error message that reveals the server type and version. Ensuring that every document directory has an "index.jsp" (or equivalent) file is one approach to mitigating the vulnerability.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Add the following section under the <web-apps> node: <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> </welcome-file-list>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000001: vSphere UI must limit the amount of time that each TCP connection is kept alive.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@connectionTimeout' - Expected result: connectionTimeout="300000" If the output does not match the expected result, this is a finding.
Discussion
Denial of service (DoS) is one threat against web servers. Many DoS attacks attempt to consume web server resources in such a way that no more resources are available to satisfy legitimate requests. In Tomcat, the "connectionTimeout" attribute sets the number of milliseconds the server will wait after accepting a connection for the request URI line to be presented. This timeout will also be used when reading the request body (if any). This prevents idle sockets that are not sending HTTP requests from consuming system resources and potentially denying new connections.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Configure the http <Connector> node with the value: 'connectionTimeout="300000"' Example: <Connector .. connectionTimeout="300000" ..>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000018: vSphere UI must limit the number of allowed connections.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@acceptCount' - Expected result: acceptCount="300" If the output does not match the expected result, this is a finding.
Discussion
Limiting the number of established connections is a basic denial-of-service protection and a best practice. Servers where the limit is too high or unlimited can potentially run out of system resources and negatively affect system availability.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to the <Connector> configured with port="${http.port}". Add or change the following value: acceptCount="300"
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000023: vSphere UI must be configured to show error pages with minimal information.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | xmllint --xpath '/Server/Service/Engine/Host/Valve[@className="org.apache.catalina.valves.ErrorReportValve"]' - Expected result: <Valve className="org.apache.catalina.valves.ErrorReportValve" showServerInfo="false"/> If the output of the command does not match the expected result, this is a finding.
Discussion
Web servers will often display error messages to client users with enough information to aid in the debugging of the error. The information given back in error messages may display the web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage. This information could be used by an attacker to blueprint what type of attacks might be successful. Therefore, vSphere UI must be configured to not show server version information in error pages.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Locate the following Host block: <Host name="localhost"" ...> ... </Host> Inside this block, add the following on a new line: <Valve className="org.apache.catalina.valves.ErrorReportValve" showServerInfo="false"/>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000008: vSphere UI application files must be verified for their integrity.
At the command prompt, execute the following command: # rpm -V vsphere-ui|grep "^..5......"|grep -E "\.war|\.jar|\.sh|\.py" If is any output, this is a finding.
Discussion
Verifying that the vSphere UI application code is unchanged from its shipping state is essential for file validation and non-repudiation of the vSphere UI. There is no reason that the MD5 hash of the rpm original files should be changed after installation, excluding configuration files.
Fix
Reinstall the VCSA or roll back to a snapshot. Modifying the vSphere UI installation files manually is not supported by VMware.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000002: vSphere UI must limit the number of concurrent connections permitted.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@maxThreads' - Expected result: maxThreads="800" If the output does not match the expected result, this is a finding.
Discussion
Resource exhaustion can occur when an unlimited number of concurrent requests are allowed on a website, facilitating a denial-of-service attack. Unless the number of requests is controlled, the web server can consume enough system resources to cause a system crash. Mitigating this kind of attack will include limiting the number of concurrent HTTP/HTTPS requests. Each incoming request requires a thread for the duration of that request. If more simultaneous requests are received than can be handled by the currently available request processing threads, additional threads will be created up to the value of the "maxThreads" attribute.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Configure each <Connector> node with the value: 'maxThreads="800"' Example: <Connector .. maxThreads="800" ..>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000010: vSphere UI must be configured to limit access to internal packages.
At the command prompt, execute the following command: # grep "package.access" /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties Expected result: package.access=sun.,org.apache.catalina.,org.apache.coyote.,org.apache.jasper.,org.apache.tomcat. If the output of the command does not match the expected result, this is a finding.
Discussion
The "package.access" entry in the "catalina.properties" file implements access control at the package level. When properly configured, a Security Exception will be reported if an errant or malicious web app attempts to access the listed internal classes directly or if a new class is defined under the protected packages. The vSphere UI comes preconfigured with the appropriate packages defined in "package.access", and this configuration must be maintained.
Fix
Navigate to and open /usr/lib/vmware-sso/vmware-sts/conf/catalina.properties. Ensure that the "package.access" line is configured as follows: package.access=sun.,org.apache.catalina.,org.apache.coyote.,org.apache.jasper.,org.apache.tomcat.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000026: vSphere UI must use a logging mechanism that is configured to allocate log record storage capacity large enough to accommodate the logging requirements of the web server.
At the command prompt, execute the following command: # rpm -V vsphere-ui|grep serviceability.xml|grep "^..5......" If the above command returns any output, this is a finding.
Discussion
To ensure that the logging mechanism used by the web server has sufficient storage capacity in which to write the logs, the logging mechanism needs to be able to allocate log record storage capacity. vSphere UI configures log sizes and rotation appropriately as part of its installation routine. Verifying that the logging configuration file (serviceability.xml) has not been modified is sufficient to determine if the logging configuration has been modified from the default.
Fix
Reinstall the VCSA or roll back to a snapshot. Modifying the vSphere UI installation files manually is not supported by VMware.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000031: vSphere UI must not be configured with the "UserDatabaseRealm" enabled.
At the command prompt, execute the following command: # grep UserDatabaseRealm /usr/lib/vmware-vsphere-ui/server/conf/server.xml If the command produces any output, this is a finding.
Discussion
The vSphere UI performs user authentication at the application level and not through Tomcat. By default, there is no configuration for the "UserDatabaseRealm" Tomcat authentication mechanism. To eliminate unnecessary features and ensure that the vSphere UI remains in its shipping state, the lack of a UserDatabaseRealm configuration must be confirmed.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Remove any and all <Realm> nodes.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000032: vSphere UI must restrict its cookie path.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/context.xml | xmllint --xpath '/Context/@sessionCookiePath' - Expected result: sessionCookiePath="/ui" If the output does not match the expected result, this is a finding.
Discussion
When the cookie parameters are not set properly (i.e., domain and path parameters), cookies can be shared within hosted applications residing on the same web server or to applications hosted on different web servers residing on the same domain. vSphere UI is bound to the "/ui" virtual path behind the reverse proxy, and its cookies are configured as such. This configuration must be confirmed and maintained.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/context.xml. Add the following configuration to the <Context> node: sessionCookiePath="/ui" Example: <Context useHttpOnly="true" sessionCookieName="VSPHERE-UI-JSESSIONID" sessionCookiePath="/ui">
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000028: vSphere UI must be configured with the appropriate ports.
At the command prompt, execute the following command: # grep '.port' /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties Expected result: http.port=5090 proxy.port=443 https.port=5443 If the output of the command does not match the expected result, this is a finding.
Discussion
Web servers provide numerous processes, features, and functionalities that use TCP/IP ports. Some of these processes may be deemed unnecessary or too unsecure to run on a production system. The ports that vSphere UI listens on are configured in the "catalina.properties" file and must be verified as accurate to their shipping state.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties. Navigate to the ports specification section. Set the vSphere UI port specifications according to the shipping configuration below: http.port=5090 proxy.port=443 https.port=5443
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000013: vSphere UI must not have the Web Distributed Authoring (WebDAV) servlet installed.
At the command prompt, execute the following command: # grep -n 'webdav' /usr/lib/vmware-vsphere-ui/server/conf/web.xml If the command produces any output, this is a finding.
Discussion
WebDAV is an extension to the HTTP protocol that, when developed, was meant to allow users to create, change, and move documents on a server, typically a web server or web share. WebDAV is not widely used and has serious security concerns because it may allow clients to modify unauthorized files on the web server and must therefore be disabled. Tomcat uses the "org.apache.catalina.servlets.WebdavServlet" servlet to provide WebDAV services. Because the WebDAV service has been found to have an excessive number of vulnerabilities, this servlet must not be installed. vSphere UI does not configure WebDAV by default.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Find the <servlet-name>webdav</servlet-name> node and remove the entire parent <servlet> block. Find the <servlet-name>webdav</servlet-name> node and remove the entire parent <servlet-mapping> block.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000021: The vSphere UI must not show directory listings.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/web.xml | sed 's/xmlns=".*"//g' | xmllint --xpath '//param-name[text()="listings"]/parent::init-param' - Expected result: <init-param> <param-name>listings</param-name> <param-value>false</param-value> </init-param> If the output of the command does not match the expected result, this is a finding.
Discussion
Enumeration techniques, such as URL parameter manipulation, rely on being able to obtain information about the web server's directory structure by locating directories without default pages. In this scenario, the web server will display to the user a listing of the files in the directory being accessed. Ensuring that directory listing is disabled is one approach to mitigating the vulnerability.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Set the <param-value> to "false" in all <param-name>listing</param-name> nodes. Note: The setting should look like the following: <init-param> <param-name>listings</param-name> <param-value>false</param-value> </init-param>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000003: vSphere UI must limit the maximum size of a POST request.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@maxPostSize' - Expected result: XPath set is empty If the output does not match the expected result, this is a finding.
Discussion
The "maxPostSize" value is the maximum size in bytes of the POST that will be handled by the container FORM URL parameter parsing. Limit its size to reduce exposure to a denial-of-service attack. If "maxPostSize" is not set, the default value of 2097152 (2MB) is used. Security Token Service is configured in its shipping state to not set a value for "maxPostSize"'.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to each of the <Connector> nodes. Remove any configuration for "maxPostSize".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000025: vSphere UI must have the debug option turned off.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/web.xml | sed 's/xmlns=".*"//g' | xmllint --xpath '//param-name[text()="debug"]/parent::init-param' - Expected result: <init-param> <param-name>debug</param-name> <param-value>0</param-value> </init-param> If no lines are returned, this is not a finding. If the output of the command does not match the expected result, this is a finding.
Discussion
Information needed by an attacker to begin looking for possible vulnerabilities in a web server includes any information about the web server and plug-ins or modules being used. When debugging or trace information is enabled in a production web server, information about the web server, such as web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage, may be displayed. Since this information may be placed in logs and general messages during normal operation of the web server, an attacker does not need to cause an error condition to gain this information. vSphere UI can be configured to set the debugging level. By setting the debugging level to zero, no debugging information will be provided to a malicious user.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Navigate to all <debug> nodes that are not set to "0". Set the <param-value> to "0" in all <param-name>debug</param-name> nodes. Note: The debug setting should look like the following: <init-param> <param-name>debug</param-name> <param-value>0</param-value> </init-param>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000029: vSphere UI must disable the shutdown port.
At the command prompt, execute the following commands: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/@port' - Expected result: port="${shutdown.port}" If the output does not match the expected result, this is a finding. # grep shutdown /etc/vmware/vmware-vmon/svcCfgfiles/vsphere-ui.json Expected result: "-Dshutdown.port=-1", If the output does not match the expected result, this is a finding.
Discussion
An attacker has at least two reasons to stop a web server. The first is to cause a denial of service, and the second is to put in place changes the attacker made to the web server configuration. If the Tomcat shutdown port feature is enabled, a shutdown signal can be sent to vSphere UI through this port. To ensure availability, the shutdown port must be disabled.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Make sure that the server port is disabled: <Server port="${shutdown.port}" …>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000015: vSphere UI must not have any symbolic links in the web content directory tree.
At the command prompt, execute the following command: # find /usr/lib/vmware-vsphere-ui/server/static/ -type l -ls If the command produces any output, this is a finding.
Discussion
A web server is designed to deliver content and execute scripts or applications on the request of a client or user. Containing user requests to files in the directory tree of the hosted web application and limiting the execution of scripts and applications guarantees that the user is not accessing information protected outside the application's realm. By checking that no symbolic links exist in the document root, the web server is protected from users jumping outside the hosted application directory tree and gaining access to the other directories, including the system root.
Fix
At the command prompt, execute the following commands: Note: Replace <file_name> for the name of any files that were returned. unlink <file_name> Repeat the commands for each file that was returned.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000016: vSphere UI directory tree must have permissions in an "out-of-the-box" state.
At the command prompt, execute the following command: # find /usr/lib/vmware-vsphere-ui/server/lib /usr/lib/vmware-vsphere-ui/server/conf -xdev -type f -a '(' -perm -o+w -o -not -user vsphere-ui -o -not -group root ')' -exec ls -ld {} \; If the command produces any output, this is a finding.
Discussion
As a rule, accounts on a web server are to be kept to a minimum. Only administrators, web managers, developers, auditors, and web authors require accounts on the machine hosting the web server. The resources to which these accounts have access must also be closely monitored and controlled. The vSphere UI files must be adequately protected with correct permissions as applied out of the box. Satisfies: SRG-APP-000211-WSR-000030, SRG-APP-000380-WSR-000072
Fix
At the command prompt, execute the following command: # chmod o-w <file> # chown vsphere-ui:root <file> Repeat the command for each file that was returned.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000009: vSphere UI plugins must be authorized before use.
At the command prompt, execute the following command: # diff <(find /usr/lib/vmware-vsphere-ui/plugin-packages/vsphere-client/plugins -type f|sort) <(rpm -ql vsphere-ui|grep "/usr/lib/vmware-vsphere-ui/plugin-packages/vsphere-client/plugins/"|sort) If there is any output, this indicates a vSphere UI plugin is present that does not ship with the VCSA. If this plugin is not known and approved, this is a finding.
Discussion
The vSphere UI ships with a number of plugins out of the box. Any additional plugins may affect the availability and integrity of the system and must be approved and documented by the ISSO before deployment.
Fix
For every unauthorized plugin returned by the check, run the following command. # rm <file>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000017: vSphere UI must fail to a known safe state if system initialization fails, shutdown fails, or aborts fail.
At the command line, execute the following command: # grep EXIT_ON_INIT_FAILURE /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties Expected result: org.apache.catalina.startup.EXIT_ON_INIT_FAILURE=true If the output of the command does not match the expected result, this is a finding.
Discussion
Determining a safe state for failure and weighing that against a potential denial of service for users depends on what type of application the web server is hosting. For the Security Token Service, it is preferable that the service abort startup on any initialization failure rather than continuing in a degraded and potentially insecure state.
Fix
Navigate to and open /etc/vmware-eam/catalina.properties. Add or change the following line: org.apache.catalina.startup.EXIT_ON_INIT_FAILURE=true
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000027: vSphere UI log files must be moved to a permanent repository in accordance with site policy.
At the command prompt, execute the following command: # grep -v "^#" /etc/vmware-syslog/stig-services-vsphere-ui.conf Expected result: input(type="imfile" File="/var/log/vmware/vsphere-ui/logs/access/localhost_access*" Tag="ui-access" Severity="info" Facility="local0") input(type="imfile" File="/var/log/vmware/vsphere-ui/logs/vsphere-ui-runtime*" Tag="ui-runtime" Severity="info" Facility="local0") If the file does not exist, this is a finding. If the output of the command does not match the expected result, this is a finding.
Discussion
vSphere UI produces a handful of logs that must be offloaded from the originating system. This information can then be used for diagnostic, forensic, or other purposes relevant to ensuring the availability and integrity of the hosted application. Satisfies: SRG-APP-000358-WSR-000163, SRG-APP-000108-WSR-000166, SRG-APP-000125-WSR-000071
Fix
Navigate to and open /etc/vmware-syslog/stig-services-vsphere-ui.conf. Create the file if it does not exist. Set the contents of the file as follows: input(type="imfile" File="/var/log/vmware/vsphere-ui/logs/access/localhost_access*" Tag="ui-access" Severity="info" Facility="local0") input(type="imfile" File="/var/log/vmware/vsphere-ui/logs/vsphere-ui-runtime*" Tag="ui-runtime" Severity="info" Facility="local0")
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000019: vSphere UI must set URIEncoding to UTF-8.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | sed '2 s/xmlns=".*"//g' | xmllint --xpath '/Server/Service/Connector[@port="${http.port}"]/@URIEncoding' - Expected result: URIEncoding="UTF-8" If the output does not match the expected result, this is a finding.
Discussion
Invalid user input occurs when a user inserts data or characters into a hosted application's data entry field and the hosted application is unprepared to process that data. This results in unanticipated application behavior, potentially leading to an application compromise. Invalid user input is one of the primary methods employed when attempting to compromise an application. An attacker can also enter Unicode characters into hosted applications in an effort to break out of the document home or root home directory or to bypass security checks. vSphere UI must be configured to use a consistent character set via the URIEncoding attribute on the Connector nodes.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to each of the <Connector> nodes. Configure each <Connector> node with the value 'URIEncoding="UTF-8"'.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000014: vSphere UI must be configured with memory leak protection.
At the command prompt, execute the following command: # grep JreMemoryLeakPreventionListener /usr/lib/vmware-vsphere-ui/server/conf/server.xml Expected result: <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener"/> If the output of the command does not match the expected result, this is a finding.
Discussion
The Java Runtime environment can cause a memory leak or lock files under certain conditions. Without memory leak protection, vSphere UI can continue to consume system resources, which will lead to "OutOfMemoryErrors" when reloading web applications. Memory leaks occur when JRE code uses the context class loader to load a singleton, as this will cause a memory leak if a web application class loader happens to be the context class loader at the time. The "JreMemoryLeakPreventionListener" class is designed to initialize these singletons when Tomcat's common class loader is the context class loader. Proper use of JRE memory leak protection will ensure that the hosted application does not consume system resources and cause an unstable environment.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to the <Server> node. Add '<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener"/>' to the <Server> node.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000030: vSphere UI must set the secure flag for cookies.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/web.xml | sed 's/xmlns=".*"//g' | xmllint --xpath '/web-app/session-config/cookie-config/secure' - Expected result: <secure>true</secure> If the output of the command does not match the expected result, this is a finding.
Discussion
The secure flag is an option that can be set by the application server when sending a new cookie to the user within an HTTP Response. The purpose of the secure flag is to prevent cookies from being observed by unauthorized parties due to the transmission of a cookie in clear text. By setting the secure flag, the browser will prevent the transmission of a cookie over an unencrypted channel. vSphere UI is configured to only be accessible over a TLS tunnel, but this cookie flag is still a recommended best practice.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Navigate to the /<web-apps>/<session-config>/<cookie-config> node and configure it as follows: <cookie-config> <http-only>true</http-only> <secure>true</secure> </cookie-config>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000004: vSphere UI must protect cookies from XSS.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/context.xml | xmllint --xpath '/Context/@useHttpOnly' - Expected result: useHttpOnly="true" If the output does not match the expected result, this is a finding.
Discussion
Cookies are a common way to save session state over the HTTP(S) protocol. If an attacker can compromise session data stored in a cookie, they are better able to launch an attack against the server and its applications. When a cookie is tagged with the "HttpOnly" flag, it tells the browser that this particular cookie should only be accessed by the originating server. Any attempt to access the cookie from client script is strictly forbidden. Satisfies: SRG-APP-000001-WSR-000002, SRG-APP-000439-WSR-000154
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/context.xml. Add the following configuration to the <Context> node: useHttpOnly="true" Example: <Context useHttpOnly="true" sessionCookieName="VSPHERE-UI-JSESSIONID" sessionCookiePath="/ui">
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000006: vSphere UI must generate log records for system startup and shutdown.
At the command prompt, execute the following command: # grep StreamRedirectFile /etc/vmware/vmware-vmon/svcCfgfiles/vsphere-ui.json Expected result: "StreamRedirectFile": "%VMWARE_LOG_DIR%/vmware/vsphere-ui/logs/vsphere-ui-runtime.log", If no log file is specified for the "StreamRedirectFile" setting, this is a finding.
Discussion
Logging must be started as soon as possible when a service starts and when a service is stopped. Many forms of suspicious actions can be detected by analyzing logs for unexpected service starts and stops. Also, by starting to log immediately after a service starts, it becomes more difficult for suspicious activity to go unlogged. On the VCSA, the "vmware-vmon" service starts up the JVMs for various vCenter processes, including vSphere UI, and the individual "json config" files control the early jvm logging. Ensuring these json files are configured correctly enable early Java stdout and stderr logging. Satisfies: SRG-APP-000089-WSR-000047, SRG-APP-000092-WSR-000055
Fix
Navigate to and open /etc/vmware/vmware-vmon/svcCfgfiles/vsphere-ui.json. Below the last line of the "PreStartCommandArg" block, add or reconfigure the following line: "StreamRedirectFile": "%VMWARE_LOG_DIR%/vmware/vsphere-ui/logs/vsphere-ui-runtime.log", Restart the appliance for changes to take effect.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000005: vSphere UI must record user access in a format that enables monitoring of remote access.
At the command prompt, execute the following command: # xmllint --format /usr/lib/vmware-vsphere-ui/server/conf/server.xml | xmllint --xpath '/Server/Service/Engine/Host/Valve[@className="org.apache.catalina.valves.AccessLogValve"]'/@pattern - Expected result: pattern="%h %{x-forwarded-for}i %l %u %t %r %s %b %{#hashedSessionId#}s %I %D" If the output does not match the expected result, this is a finding.
Discussion
Remote access can be exploited by an attacker to compromise the server. By recording all remote access activities, it will be possible to determine the attacker's location, intent, and degree of success. Tomcat can be configured with an "AccessLogValve", a component that can be inserted into the request processing pipeline to provide robust access logging. The AccessLogValve creates log files in the same format as those created by standard web servers. When AccessLogValve is properly configured, log files will contain all the forensic information necessary in the case of a security incident. Satisfies: SRG-APP-000016-WSR-000005, SRG-APP-000089-WSR-000047, SRG-APP-000095-WSR-000056, SRG-APP-000096-WSR-000057, SRG-APP-000097-WSR-000058, SRG-APP-000098-WSR-000059, SRG-APP-000098-WSR-000060, SRG-APP-000099-WSR-000061, SRG-APP-000100-WSR-000064, SRG-APP-000374-WSR-000172, SRG-APP-000375-WSR-000171
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Ensure the log pattern in the "org.apache.catalina.valves.AccessLogValve" node is set to the following: pattern="pattern="%h %{x-forwarded-for}i %l %u %t %r %s %b %{#hashedSessionId#}s %I %D""
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000011: vSphere UI must have Multipurpose Internet Mail Extensions (MIME) that invoke OS shell programs disabled.
At the command prompt, execute the following command: # grep -En '(x-csh<)|(x-sh<)|(x-shar<)|(x-ksh<)' /usr/lib/vmware-vsphere-ui/server/conf/web.xml If the command produces any output, this is a finding.
Discussion
MIME mappings tell the vSphere UI what type of program various file types and extensions are and what external utilities or programs are needed to execute the file type. By ensuring that various shell script MIME types are not included in web.xml, the server is protected against malicious users tricking the server into executing shell command files.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/web.xml. Remove any and all of the following nodes lines: <mime-type>application/x-csh</mime-type> <mime-type>application/x-shar</mime-type> <mime-type>application/x-sh</mime-type> <mime-type>application/x-ksh</mime-type>
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
VCUI-67-000024: vSphere UI must not enable support for TRACE requests.
At the command prompt, execute the following command: # grep allowTrace /usr/lib/vmware-vsphere-ui/server/conf/server.xml If "allowTrace" is set to "true", this is a finding. If no line is returned, this is NOT a finding.
Discussion
"Trace" is a technique for a user to request internal information about Tomcat. This is useful during product development but should not be enabled in production. Allowing an attacker to conduct a Trace operation against the Security Token Service will expose information that would be useful to perform a more targeted attack. vSphere UI provides the "allowTrace" parameter as a means to disable responding to Trace requests.
Fix
Navigate to and open /usr/lib/vmware-vsphere-ui/server/conf/server.xml. Navigate to and locate: 'allowTrace="true"' Remove the 'allowTrace="true"' setting.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None