Title

CICS System Initialization Table (SIT) parameter values must be specified in accordance with proper security requirements. (Cat II impact)

Discussion

The CICS SIT is used to define system operation and configuration parameters of a CICS system. Several of these parameters control the security within a CICS region. Failure to code the appropriate values could result in unexpected operations and degraded security. This exposure may result in unauthorized access impacting the confidentiality, integrity, and availability of the CICS region, applications, and customer data.

Check Content

Refer to the following report produced by the z/OS Data Collection: - EXAM.RPT(CICSPROC) Refer to the following report produced by the CICS Data Collection: - CICS.RPT(DFHSITxx) Refer to the CICS Systems Programmer Worksheets filled out from previous vulnerability ZCIC0010. Refer to the CICS region SYSLOG - (Alternate source of SIT parameters) be sure to process DFHSIT based on the order specified. The system initialization parameters are processed in the following order, with later system initialization parameter values overriding those specified earlier. CICS system initialization parameters are specified in the following ways: In the system initialization table, loaded from a library in the STEPLIB concatenation of the CICS startup procedure. In the PARM parameter of the EXEC PGM=DFHSIP statement of the CICS startup procedure. In the SYSIN data set defined in the startup procedure (but only if SYSIN is coded in the PARM parameter). Ensure the following CICS System Initialization Table (SIT) parameter settings are specified for each CICS region. If the following guidance is true, this is not a finding. ___ SEC=YES - If SEC is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below is the hex and bit settings for this flag. X’80’ EQU B’10000000’ External Security Requested ___ DFLTUSER=<parameter> - If DFLTUSER is not coded in the CICS region startup JCL, go to offset x’118’ from the beginning on the SIT dump (record sequence number - 6) for a length of 8 bytes. The value will be the CICS default userid. ___ XUSER=YES - If XUSER is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below is the hex and bit settings for this flag. X’04’ EQU B’00000100’ Surrogate User Checking required ___ SNSCOPE=NONE|CICS|MVSIMAGE|SYSPLEX - If SNSCOPE is not coded in the CICS region startup JCL, go to offset x’124’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the signon scope byte flag. Ensure that users cannot sign on to more than one CICS production region within the scope of a single CICS region, a single z/OS image, or a sysplex. Below are listed the hex and bit settings for this flag: X’01’ EQU 1 SIGNON SCOPE = NONE X’02’ EQU 2 SIGNON SCOPE = CICS X’03’ EQU 3 SIGNON SCOPE = MVSIMAGE X’04’ EQU 4 SIGNON SCOPE = SYSPLEX Note: SNSCOPE=NONE is only allowed with test/development regions. ___ XTRAN=YES|ssrrTRN - If XTRAN is not coded in the CICS region startup JCL, go to offset x’CA’ from the beginning on the SIT dump (record sequence number - 6) for a length of 7 bytes. The value will be the resource class name used for that region. If XTRAN=YES is coded, c’CICSTRN’ will be present. ___ SECPRFX=YES - If SECPRFX is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below are the hex and bit settings for this flag. X’40’ EQU B’01000000’ Resource Prefix Required If XTRAN=ssrrTRN is specified, resource prefixing (e.g., SECPRFX=YES) is not required to be enabled. Also, CICS regions cannot share the same resource class if resource prefixing is not active.

Fix Text

Ensure that CICS System Initialization Table (SIT) parameter values are specified using the following guidance. The system initialization parameters are processed in the following order, with later system initialization parameter values overriding those specified earlier. CICS system initialization parameters are specified in the following ways: In the system initialization table, loaded from a library in the STEPLIB concatenation of the CICS startup procedure. In the PARM parameter of the EXEC PGM=DFHSIP statement of the CICS startup procedure. In the SYSIN data set defined in the startup procedure (but only if SYSIN is coded in the PARM parameter). SEC=YES - If SEC is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below are is the hex and bit settings for this flag. X’80’ EQU B’10000000’ External Security Requested <<=== X’40’ EQU B’01000000’ Resource Prefix Required X’10’ EQU B’00010000’ RACLIST class APPCLU required X’08’ EQU B’00001000’ ESM INSTLN data is required X’04’ EQU B’00000100’ Surrogate User Checking required X’02’ EQU B’00000010’ Always enact resource check X’01’ EQU B’00000001’ Always enact command check DFLTUSER=<parameter> - If DFLTUSER is not coded in the CICS region startup JCL, go to offset x’118’ from the beginning on the SIT dump (record sequence number - 6) for a length of 8 bytes. The value will be the CICS default userid. XUSER=YES - If XUSER is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below is the hex and bit settings for this flag. X’80’ EQU B’10000000’ External Security Requested X’40’ EQU B’01000000’ Resource Prefix Required X’10’ EQU B’00010000’ RACLIST class APPCLU required X’08’ EQU B’00001000’ ESM INSTLN data is required X’04’ EQU B’00000100’ Surrogate User Checking required <<=== X’02’ EQU B’00000010’ Always enact resource check X’01’ EQU B’00000001’ Always enact command check SNSCOPE=NONE|CICS|MVSIMAGE|SYSPLEX If SNSCOPE is not coded in the CICS region startup JCL, go to offset x’124’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the signon scope byte flag. Ensure that users cannot sign on to more than one CICS production region within the scope of a single CICS region, a single z/OS image, or a sysplex. Below are the hex settings for this flag: X’01’ EQU 1 SIGNON SCOPE = NONE X’02’ EQU 2 SIGNON SCOPE = CICS X’03’ EQU 3 SIGNON SCOPE = MVSIMAGE X’04’ EQU 4 SIGNON SCOPE = SYSPLEX Note: SNSCOPE=NONE is only allowed with test/development regions. XTRAN=YES|ssrrTRN - If XTRAN is not coded in the CICS region startup JCL, go to offset x’CA’ from the beginning on the SIT dump (record sequence number - 6) for a length of 7 bytes. The value will be the resource class name used for that region. If XTRAN=YES is coded, c’CICSTRN’ will be present. SECPRFX=YES - If SECPRFX is not coded in the CICS region startup JCL, go to offset x’117’ from the beginning on the SIT dump (record sequence number - 6) for a length of 1. This is the security byte flag. Below are the hex and bit settings for this flag with the resource prefixing setting bolded: X’80’ EQU B’10000000’ External Security Requested X’40’ EQU B’01000000’ Resource Prefix Required <<=== X’10’ EQU B’00010000’ RACLIST class APPCLU required X’08’ EQU B’00001000’ ESM INSTLN data is required X’04’ EQU B’00000100’ Surrogate User Checking required X’02’ EQU B’00000010’ Always enact resource check X’01’ EQU B’00000001’ Always enact command check Note: If XTRAN=ssrrTRN is specified, resource prefixing (e.g., SECPRFX=YES) is not required to be enabled. Also, CICS regions cannot share the same resource class if resource prefixing is not active.

Additional Identifiers

Rule ID: SV-7530r3_rule

Vulnerability ID: V-302

Group Title: ZCIC0030

Expert Comments

CCIs tied to check.

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