CVE-2021-44731: snapd could be made to escalate privileges and run programs as administrator
A race condition existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap. This could allow a local attacker to gain root privileges by bind-mounting their own contents inside the snap's private mount namespace and causing snap-confine to execute arbitrary code and hence gain privilege escalation. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2021-44731?
CVE-2021-44731 is a vulnerability that existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap, allowing a local attacker to gain root privileges.
How severe is CVE-2021-44731?
CVE-2021-44731 has a severity score of 7.8 (high).
Which software versions are affected by CVE-2021-44731?
The affected software versions include snapd 2.37.4-1+deb10u1, 2.37.4-1+deb10u3, 2.49-1+deb11u2, 2.57.6-1, and 2.60.2-1 on Debian, as well as snapd 2.54.3+18.04 on Ubuntu 18.04 LTS, snapd 2.54.3+20.04 on Ubuntu 20.04 LTS, snapd 2.54.3+21.10.1 on Ubuntu 21.10, and snapd 2.54.3 (upstream version) on Ubuntu (all versions).
How can I fix CVE-2021-44731?
To fix CVE-2021-44731, update snapd to version 2.54.3+18.04 on Ubuntu 18.04 LTS, 2.54.3+20.04 on Ubuntu 20.04 LTS, 2.54.3+21.10.1 on Ubuntu 21.10, or 2.54.3 (upstream version) on Ubuntu (all versions). For Debian, update to snapd versions 2.37.4-1+deb10u1, 2.37.4-1+deb10u3, 2.49-1+deb11u2, 2.57.6-1, or 2.60.2-1.
Where can I find more information about CVE-2021-44731?
You can find more information about CVE-2021-44731 at the following references: [1] http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html [2] http://seclists.org/fulldisclosure/2022/Dec/4 [3] http://www.openwall.com/lists/oss-security/2022/02/18/2