CVE-2020-11931 | Ubuntu modifications to pulseaudio to provide snap security enforcement could be unloaded

An Ubuntu-specific modification to Pulseaudio to provide security mediation for Snap-packaged applications was found to have a bypass of intended access restriction for snaps which plugs any of pulseaudio, audio-playback or audio-record via unloading the pulseaudio snap policy module. This issue affects: pulseaudio 1:8.0 versions prior to 1:8.0-0ubuntu3.12; 1:11.1 versions prior to 1:11.1-1ubuntu7.7; 1:13.0 versions prior to 1:13.0-1ubuntu1.2; 1:13.99.1 versions prior to 1:13.99.1-1ubuntu3.2;

Published: 2020-05-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-11931 is rated Low Risk (16/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.04%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-11931

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2023-03-07 0.89% 0.04% -0.84%
2 2022-04-01 1.40% 0.89% -0.52%
3 2022-02-04 — 1.40% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-11931

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 1.4 [email protected]
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2020-11931

OS Trackers for CVE-2020-11931

vendor priority summary link
ubuntu medium CVE-2020-11931 medium priority: Ubuntu including 1 source packages (pulseaudio), 6 status rows across 6 suites (bionic, eoan, focal, trusty, upstream, xenial): released 4, DNE 1, not-affected 1. https://ubuntu.com/security/CVE-2020-11931

Affected software / configurations for CVE-2020-11931

Vendor Product Version Raw CPE
pulseaudio pulseaudio <= 1.8.0 cpe:2.3:a:pulseaudio:pulseaudio:*:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*

References for CVE-2020-11931

cvelogic Threat Intelligence