Title

z/OS UNIX resources must be protected in accordance with security requirements. (Cat I impact)

Discussion

z/OS UNIX ACP-defined resources consist of sensitive capabilities including SUPERUSER, daemon, and numerous file manipulation privileges. Missing or inaccurate protection of these resources could allow a user to access sensitive data, modify or delete data and operating system controls, or issue commands that could negatively impact system availability.

Check Content

a) Refer to the following report produced by the ACF2 Data Collection and Data Set and Resource Data Collection: - SENSITVE.RPT(SURROGAT) - ACF2CMDS.RPT(RESOURCE) – Alternate report Automated Analysis Refer to the following report produced by the Data Set and Resource Data Collection: - PDI(ZUSS0022) b) If the ACF2 rules for all BPX.SRV.user TYPE(SUR) resources specify a default access of NONE, there is NO FINDING. c) If the ACF2 rules for all BPX.SRV.user TYPE(SUR) resources restrict access to system software processes (e.g., web servers) that act as servers under z/OS UNIX, there is NO FINDING. d) If (b) or (c) above is untrue, this is a FINDING.

Fix Text

The Systems Programmer and IAO will ensure that BPX. SRV.userid resources are properly protected and access is restricted to appropriate system tasks or systems programming personnel. SURROGAT class BPX resources are used in conjunction with server applications that are performing tasks on behalf of client users that may not supply an authenticator to the server. This can be the case when clients are otherwise validated or when the requested service is performed from userids representing groups. The default access for each BPX.SRV.userid resource must be no access. Access can be permitted only to system software processes that act as servers under OS/390 UNIX (e.g., web servers). Example: SET R(SUR) $KEY(BPX) TYPE(SUR) SRV.INTERNAL UID(FJB****STC******IMWEBSRV) SERVICE(READ) LOG SRV.PRIVATE UID(FJB****STC******IMWEBSRV) SERVICE(READ) LOG SRV.PUBLIC UID(FJB****STC******IMWEBSRV) SERVICE(READ) LOG SRV.WEBADM UID(FJB****STC******IMWEBSRV) SERVICE(READ) LOG - UID(*) PREVENT

Additional Identifiers

Rule ID: SV-7273r3_rule

Vulnerability ID: V-6970

Group Title: ZUSS0022

Expert Comments

CCIs tied to check.

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