SB2024012477 - Red Hat Enterprise Linux 9 update for rpm
Published: January 24, 2024
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2021-35937)
CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local privileged user to escalate privileges on the system.
The vulnerability exist due to race condition. A local privileged user can bypass the checks that were introduced in response to CVE-2017-7500 and CVE-2017-7501, potentially gaining root privileges.
2) Link following (CVE-ID: CVE-2021-35938)
CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local privileged user to escalate privileges on the system.
The vulnerability occurs when rpm sets the desired permissions and credentials after installing a file. A local privileged user can use this flaw to exchange the original file with a symbolic link to a security-critical file and escalate their privileges on the system.
3) Link following (CVE-ID: CVE-2021-35939)
CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local privileged user to escalate privileges on the system.
The vulnerability exist due to fix for CVE-2017-7500 and CVE-2017-7501 was incomplete: the check was only implemented for the parent directory of the file to be created. A local privileged user who owns another ancestor directory could potentially use this flaw to gain root privileges.
Remediation
Install update from vendor's website.