Check: RACF-TN-000020
IBM z/OS RACF STIG:
RACF-TN-000020
(in versions v8 r14 through v7 r1)
Title
IBM z/OS SSL encryption options for the TN3270 Telnet Server must be specified properly for each statement that defines a SECUREPORT or within the TELNETGLOBALS. (Cat II impact)
Discussion
During the SSL connection process a mutually acceptable encryption algorithm is selected by the server and client. This algorithm is used to encrypt the data that subsequently flows between the two. However, the level or strength of encryption can vary greatly. Certain configuration options can allow no encryption to be used and others can allow a relatively weak 40-bit algorithm to be used. Failure to properly enforce adequate encryption strength could result in the loss of data privacy. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000396-GPOS-00176, SRG-OS-000478-GPOS-00223, SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190, SRG-OS-000478-GPOS-00223
Check Content
Refer to the Profile configuration file specified on the PROFILE DD statement in the TCPIP started task JCL. If the following items are in effect for the configuration specified in the TCP/IP Profile configuration file, this is not a finding. NOTE: If an INCLUDE statement is coded in the TCP/IP Profile configuration file, the data set specified on this statement must be checked for the following items as well. NOTE: FIPS 140-2 minimum encryption is the accepted level of encryption and will override this requirement if greater. The TELNETGLOBALS block that specifies an ENCRYPTION statement states one or more of the below cipher specifications. Each TELNETPARMS block that specifies the SECUREPORT statement, specifies an ENCRYPTION statement states one or more of the below cipher specifications. And the TELNETGLOBALS block does or does not specify an ENCRYPTION statement. Cipher Specifications SSL_3DES_SHA SSL_AES_256_SHA SSL_AES_128_SHA
Fix Text
Configure the SECUREPORT and TELNETPARMS ENCRYPTION statements and/or the TELNETGLOBALS statement in the PROFILE.TCPIP file to conform to the requirements specified below. The TELNETGLOBALS block may specify an ENCRYPTION statement that specifies one or more of the below cipher specifications. Each TELNETPARMS block that specifies the SECUREPORT statement, an ENCRYPTION statement is coded with one or more of the below cipher specifications. And the TELNETGLOBALS block does or does not specify an ENCRYPTION statement. To prevent the use of non FIPS 140-2 encryption, the TELNETGLOBALS block and/or each TELNETPARMS block that specifies an ENCRYPTION statement will specify one or more of the following cipher specifications: Cipher Specifications SSL_3DES_SHA SSL_AES_256_SHA SSL_AES_128_SHA Note: Always check for the minimum allowed in FIPS 140-2.
Additional Identifiers
Rule ID: SV-223831r877398_rule
Vulnerability ID: V-223831
Group Title: SRG-OS-000033-GPOS-00014
Expert Comments
CCIs
| Number | Definition |
|---|---|
| CCI-000068 |
The information system implements cryptographic mechanisms to protect the confidentiality of remote access sessions. |
| CCI-000803 |
The information system implements mechanisms for authentication to a cryptographic module that meet the requirements of applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance for such authentication. |
| CCI-001453 |
The information system implements cryptographic mechanisms to protect the integrity of remote access sessions. |
| CCI-002418 |
The information system protects the confidentiality and/or integrity of transmitted information. |
| CCI-002420 |
The information system maintains the confidentiality and/or integrity of information during preparation for transmission. |
| CCI-002421 |
The information system implements cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by organization-defined alternative physical safeguards. |
| CCI-002422 |
The information system maintains the confidentiality and/or integrity of information during reception. |
| CCI-002450 |
The information system implements organization-defined cryptographic uses and type of cryptography required for each use in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. |
| CCI-002890 |
The information system implements cryptographic mechanisms to protect the integrity of nonlocal maintenance and diagnostic communications. |
| CCI-003123 |
The information system implements cryptographic mechanisms to protect the confidentiality of nonlocal maintenance and diagnostic communications. |
Controls
| Number | Title |
|---|---|
| AC-17 (2) |
Protection Of Confidentiality / Integrity Using Encryption |
| IA-7 |
Cryptographic Module Authentication |
| MA-4 (6) |
Cryptographic Protection |
| SC-8 |
Transmission Confidentiality And Integrity |
| SC-8 (1) |
Cryptographic Or Alternate Physical Protection |
| SC-8 (2) |
Pre / Post Transmission Handling |
| SC-13 |
Cryptographic Protection |