SB2022021748 - Fedora 34 update for snapd
Published: February 17, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Race condition (CVE-ID: CVE-2021-44731)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in the snap-confine binary when preparing a private mount namespace for a snap.. A local user can bind-mount their own contents inside the snap's private mount namespace and execute arbitrary code with root privileges.
2) UNIX hardlink following (CVE-ID: CVE-2021-44730)
CWE-ID: CWE-62 - UNIX Hard Link
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a hardlink following issue within the the snap-confine binary. A local user can create a hardlink to system binaries and execute them with elevated privileges.
3) Input validation error (CVE-ID: CVE-2021-4120)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to insufficient validation of snap content interface and layout paths. A local user can inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and execute arbitrary code with elevated privileges.
Remediation
Install update from vendor's website.