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Security Bulletin: Stack overflow via TIS_CODESET environment variable in IBM Workload Scheduler

Security Bulletin


Stack overflow via TIS_CODESET environment variable in IBM Workload Scheduler chkhltst program on Linux, Unix.

Vulnerability Details

CVEID:   CVE-2021-20349
DESCRIPTION:   IBM Tivoli Workload Scheduler is vulnerable to a stack-based buffer overflow, caused by improper bounds checking. A local attacker could overflow a buffer and gain lower level privileges.
CVSS Base score: 5.9
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)

Affected Products and Versions

Affected Product(s)Version(s)
IBM Workload Scheduler9.5
IBM Workload Scheduler9.4


APAR IJ30794 has been opened to address CVE-2021-20349.
Apar IJ30794 has been included in IBM Workload Scheduler and it is already available on FixCentral for 9.4 release (940-TIV-TWS-FP7-IJ30794) to be applied on top of

Workarounds and Mitigations


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This vulnerability was reported to IBM by Maciej Grabiec and Lukasz Plonka.

Change History

05 Aug 2021: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.


Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

Document Location


[{"Business Unit":{"code":"BU004","label":"Hybrid Cloud"},"Product":{"code":"SSCHEZ","label":"IBM Workload Automation"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.5, 9.4","Edition":""}]

Document Information

Modified date:
09 August 2021