Security Bulletin: Vulnerability in polkit affects Cloud Pak System ( CVE-2021-4034)

Security Bulletin

Summary

Polkit is used by IBM Cloud System OS. This security bulletin service applies to IBM Cloud System , IBM Cloud System Software and IBM Cloud System Software Suite.

Vulnerability Details

CVEID: CVE-2021-4034
DESCRIPTION: Polkit could allow a local authenticated attacker to gain elevated privileges on the system, caused by incorrect handling of the argument vectors in the pkexec utility. By crafting environment variables in a specific way, an attacker could exploit this vulnerability to execute commands with root privileges.
CVSS Base score: 7.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/218087 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Affected Product(s)	Version(s)
IBM Cloud Pak System	2.3.3.0, 2.3.3.1, 2.3.3.2, 2.3.3.3, 2.3.3.4
IBM Cloud Pak System	2.3.0.1, 2.3.1.1, 2.3.2.0

Remediation/Fixes

For unsupported version/release/platform IBM recommends upgrading to a fixed, supported version of the product.

For IBM Cloud Pak System v2.3.0.1, v2.3.1.1, v2.3.2.0, v2.3.3.0, v.2.3.3.1, v.2.3.3.2, v.2.3.3.3, v2.3.3.3 Interim Fix 1, v2.3.3.4

upgrade to IBM Cloud Pak System v2.3.3.5 at Fix Central

Information on upgrading : http://www.ibm.com/support/docview.wss?uid=ibm10887959

Workarounds and Mitigations

Temporary mitigation for the reported CVE-2021-4034 remove the SUID-bit from pkexec as follows:

As "root" user execute the command

# chmod 0755 /usr/bin/pkexec

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References

Complete CVSS v3 Guide
On-line Calculator v3

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Change History

31 May 2022: 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.

Disclaimer

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

Document Location

Worldwide

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Tips

Security Bulletin: Vulnerability in polkit affects Cloud Pak System ( CVE-2021-4034)