Vulnerability in Canonical Ltd. Snapd
CVE-2021-44731
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
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.010 (60.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 60.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000
Affected products
- Canonical Ltd. Snapd — versions unspecified
- Canonical Snapd
- Canonical Ubuntu Linux — versions 18.04, 20.04, 21.10
- Debian Linux — versions 10.0, 11.0
- Fedoraproject Fedora — versions 34, 35
Weakness classification (CWE)
Public proof-of-concept exploits
References
- ubuntu.com/security/notices/USN-5292-1 (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2022/02/18/2 (mailing-list, Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.debian.org/security/2022/dsa-5080 (vendor-advisory, Third Party Advisory, Issue Tracking)
- www.openwall.com/lists/oss-security/2022/02/23/1 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2022/02/23/2 (mailing-list, Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2022/11/30/2 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- seclists.org/fulldisclosure/2022/Dec/4 (mailing-list, Exploit, Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perm… (Exploit, VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-44731?
- CVE-2021-44731 is a high-severity vulnerability in Canonical Ltd. Snapd, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.8/10. Published 2022-02-17.
- How severe is CVE-2021-44731?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2021-44731 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.