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OpenAdvisories
High · 7.8 Public exploit CVE-2021-44731 EUVD-2021-31546GHSA-m3j9-xfh2-hrgc

snapd could be made to escalate privileges and run programs as administrator

Published Feb 17, 2022 · Updated Aug 4, 2024 · Assigned by canonical

Vendor: Canonical Product: snapd Package: snapd Package: snapd Ecosystem: Debian Ecosystem: Ubuntu

Description

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 products

VendorProductAffectedFixed
Canonical snapd unspecified – ≤ 2.54.2 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗
ReleasePackageFixed inAdvisory
Debian 14 snapd 2.54.3-1 —
Debian 13 snapd 2.54.3-1 —
Debian 12 snapd 2.54.3-1 —
Debian 11 snapd 2.49-1+deb11u1 DSA-5080-1
Debian 10 snapd 2.37.4-1+deb10u1 DSA-5080-1

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS snapd 2.54.3+20.04.1 USN-5292-2, USN-5292-1
Ubuntu 18.04 LTS snapd 2.54.3+18.04 USN-5292-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 16.04 LTS snapd 2.54.3+16.04~esm2 USN-5292-3
Ubuntu Pro 14.04 LTS snapd 2.54.3+14.04~esm1 USN-5292-3

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 4

References