Title

The Syslog daemon must be properly defined and secured. (Cat II impact)

Discussion

The Syslog daemon, known as syslogd, is a zOS UNIX daemon that provides a central processing point for log messages issued by other zOS UNIX processes. It is also possible to receive log messages from other network-connected hosts. Some of the IBM Communications Server components that may send messages to syslog are the FTP, TFTP, zOS UNIX Telnet, DNS, and DHCP servers. The messages may be of varying importance levels including general process information, diagnostic information, critical error notification, and audit-class information. Primarily because of the potential to use this information in an audit process, there is a security interest in protecting the syslogd process and its associated data. The Syslog daemon requires special privileges and access to sensitive resources to provide its system services. Failure to properly define and control the Syslog daemon could lead to unauthorized access. This exposure may result in the compromise of the integrity and availability of the operating system environment, ACP, and customer data.

Check Content

Refer to the following reports produced by the RACF Data Collection: - RACFCMDS.RPT(LISTUSER) - DSMON.RPT(RACSPT) Refer to the following report produced by the UNIX System Services Data Collection: - USSCMDS.RPT(ERC) - Refer to this report if the Syslog daemon is started from /etc/rc. Refer to the JCL procedure libraries defined to JES2. Ensure that the Syslog daemon is properly defined and protected as stated below. If the following guidance is true, this is not a finding. ___ The Syslog daemon userid is SYSLOGD. ___ The SYSLOGD userid is defined as a PROTECTED userid. ___ The SYSLOGD userid has UID(0), HOME(‘/’), and PROGRAM(‘/bin/sh’) specified in the OMVS segment. ___ A matching entry mapping the SYSLOGD started proc to the SYSLOGD userid is in the STARTED resource class. ___ If Syslog daemon is started from /etc/rc then ensure that the _BPX_JOBNAME and _BPX_USERID environment variables are assigned a value of SYSLOGD.

Fix Text

The IAO working with the systems programmer responsible for supporting IBM Comm Server will ensure that Syslog daemon runs under its own user account. Specifically, it does not share the account defined for the z/OS UNIX kernel. The Syslog daemon userid is SYSLOGD. The SYSLOGD userid is defined as a PROTECTED userid. The SYSLOGD userid has UID(0), HOME(‘/’), and PROGRAM(‘/bin/sh’) specified in the OMVS segment. To set up and use as an MVS Started Proc, the following sample commands are provided: AU SYSLOGD NAME('stc, tcpip') NOPASSWORD NOOIDCARD DFLTGRP(STC) – OWNER(STC) DATA('Reference ISLG0020 for proper setup ') ALU SYSLOGD DFLTGRP(stctcpx) ALU SYSLOGD OMVS(UID(0) HOME('/') PROGRAM('/bin/sh')) CO SYSLOGD GROUP(stctcpx) OWNER(stctcpx) A matching entry mapping the SYSLOGD started proc to the SYSLOGD userid is in the STARTED resource class. RDEF STARTED SYSLOGD.** UACC(NONE) OWNER(ADMIN) AUDIT(ALL(READ)) STDATA(USER(SYSLOGD) GROUP(STC)) If /etc/rc is used to start the Syslog daemon ensure that the _BPX_JOBNAME and _BPX_ USERID environment variables are assigned a value of SYSLOGD.

Additional Identifiers

Rule ID: SV-7079r3_rule

Vulnerability ID: V-3243

Group Title: ISLG0020

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.