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
References (10)
Core 10
Core References
Mailing List, Third Party Advisory mailing-list
http://www.openwall.com/lists/oss-security/2022/02/18/2
Mailing List, Third Party Advisory vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3QTBN7LLZISXIA4KU4UKDR27Q5PXDS2U/
Mailing List, Third Party Advisory vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XCGHG6LJAVJJ72TMART6A7N4Z6MSTGI7/
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
Exploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html
Patch, Vendor Advisory
https://ubuntu.com/security/notices/USN-5292-1
Scores
CVSS v3
7.8
EPSS
0.0106
EPSS Percentile
77.9%
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