snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

The remote Ubuntu 16.04 ESM host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5292-3 advisory.

    USN-5292-1 fixed several vulnerabilities in snapd. This update provides the corresponding update for     Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.



Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5292-2 advisory.

    USN-5292-1 fixed vulnerabilities in snapd. This update provides the corresponding update for the riscv64     architecture.



Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5292-1 advisory.

    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)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
158162	Ubuntu 16.04 ESM : snapd vulnerabilities (USN-5292-3)	Nessus	Ubuntu Local Security Checks	high
158160	Ubuntu 20.04 LTS : snapd vulnerabilities (USN-5292-2)	Nessus	Ubuntu Local Security Checks	high
158135	Ubuntu 18.04 LTS / 20.04 LTS : snapd vulnerabilities (USN-5292-1)	Nessus	Ubuntu Local Security Checks	high

Detections

Analytics

CVE-2021-4120

high

Tenable Plugins

high

high

high