High severity · published Feb 17, 2022
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
7.8
CVSS
1%
EPSS
No
On KEV
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
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 61% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
10.0; 11.0 · source: NVD
FE
Fedora · Fedoraproject
34; 35 · source: NVD
SN
Snapd · Canonical
through 2.54.2 · source: NVD
UL
Ubuntu Linux · Canonical
18.04; 20.04; 21.10 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-44731
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-44731
Exploit
http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html
Exploit
http://seclists.org/fulldisclosure/2022/Dec/4
Mailing List
http://www.openwall.com/lists/oss-security/2022/02/18/2
Exploit
http://www.openwall.com/lists/oss-security/2022/02/23/1
Mailing List
http://www.openwall.com/lists/oss-security/2022/02/23/2
Exploit
http://www.openwall.com/lists/oss-security/2022/11/30/2
More from Snapd
10.0
CVE-2023-1523
Using the TIOCLINUX ioctl request, a malicious snap could inject contents into the input of the controlling terminal which could allow it to cause arbitrary commands to be…
9.8
CVE-2019-7304
Canonical snapd before version 2.37.1 incorrectly performed socket owner validation, allowing an attacker to run arbitrary commands as root
8.8
CVE-2020-27352
When generating the systemd service units for the docker snap (and other similar snaps), snapd does not specify Delegate=yes - as a result systemd will move processes from the…
8.8
CVE-2021-44730
snapd 2.54.2 did not properly validate the location of the snap-confine binary
8.2
CVE-2024-1724
In snapd versions prior to 2.62, when using AppArmor for enforcement of sandbox permissions, snapd failed to restrict writes to the $HOME/bin path