CVE-2021-44731

HIGH

snapd < 2.54.3 - Local Privilege Escalation via Race Condition in snap-confine

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2021-44731. PoCs published by deeexcee-io.

AI-analyzed exploit summary This repository contains a functional local privilege escalation (LPE) exploit for CVE-2021-44731, targeting vulnerable versions of snap-confine (2.54.2 and lower). The exploit leverages improper SUID handling to gain root access via a reverse shell.

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

Exploits (1)

nomisec WORKING POC 3 stars
by deeexcee-io · poc
https://github.com/deeexcee-io/CVE-2021-44731-snap-confine-SUID

This repository contains a functional local privilege escalation (LPE) exploit for CVE-2021-44731, targeting vulnerable versions of snap-confine (2.54.2 and lower). The exploit leverages improper SUID handling to gain root access via a reverse shell.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: snap-confine <= 2.54.2
No auth needed
Prerequisites: Vulnerable snap-confine binary present on the system · GCC for compiling the C component
mistral-large-3 · analyzed Feb 16, 2026 Full analysis →

References (10)

Core 10
Core References
Mailing List, Third Party Advisory mailing-list
http://www.openwall.com/lists/oss-security/2022/02/18/2
Issue Tracking, Third Party Advisory vendor-advisory
https://www.debian.org/security/2022/dsa-5080
Exploit, Mailing List, Third Party Advisory mailing-list
http://www.openwall.com/lists/oss-security/2022/02/23/1
Mailing List, Third Party Advisory mailing-list
http://www.openwall.com/lists/oss-security/2022/02/23/2
Exploit, Mailing List, Third Party Advisory mailing-list
http://www.openwall.com/lists/oss-security/2022/11/30/2
Exploit, Mailing List, Third Party Advisory mailing-list
http://seclists.org/fulldisclosure/2022/Dec/4

Scores

CVSS v3 7.8
EPSS 0.0095
EPSS Percentile 57.2%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Details

CWE
CWE-362
Status published
Products (8)
canonical/snapd < 2.54.2
canonical/ubuntu_linux 18.04
canonical/ubuntu_linux 20.04
canonical/ubuntu_linux 21.10
debian/debian_linux 10.0
debian/debian_linux 11.0
fedoraproject/fedora 34
fedoraproject/fedora 35
Published Feb 17, 2022
Tracked Since Feb 18, 2026