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Ubuntu Security Notice USN-5292-2
February 18, 2022
snapd vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in snapd.
Software Description:
- snapd: Daemon and tooling that enable snap packages
Details:
USN-5292-1 fixed vulnerabilities in snapd. This update provides the
corresponding update for the riscv64 architecture.
Original advisory details:
James Troup discovered that snap did not properly manage the
permissions for the snap directories. A local attacker could possibly
use this issue to expose sensitive information. (CVE-2021-3155)
Ian Johnson discovered that snapd did not properly validate content
interfaces and layout paths. A local attacker could possibly use this
issue to inject arbitrary AppArmor policy rules, resulting in a bypass
of intended access restrictions. (CVE-2021-4120)
The Qualys Research Team discovered that snapd did not properly
validate the location of the snap-confine binary. A local attacker
could possibly use this issue to execute other arbitrary binaries and
escalate privileges. (CVE-2021-44730)
The Qualys Research Team discovered that a race condition existed in
the snapd snap-confine binary when preparing a private mount namespace
for a snap. A local attacker could possibly use this issue to escalate
privileges and execute arbitrary code. (CVE-2021-44731)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 20.04 LTS:
snap-confine 2.54.3+20.04.1
snapd 2.54.3+20.04.1
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-5292-2
https://ubuntu.com/security/notices/USN-5292-1
CVE-2021-3155, CVE-2021-4120, CVE-2021-44730, CVE-2021-44731
Package Information:
https://launchpad.net/ubuntu/+source/snapd/2.54.3+20.04.1
