CVE-2021-41141 | Missing release of locks in PJSIP

PJSIP is a free and open source multimedia communication library written in the C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In various parts of PJSIP, when error/failure occurs, it is found that the function returns without releasing the currently held locks. This could result in a system deadlock, which cause a denial of service for the users. No release has yet been made which contains the linked fix commit. All versions up to an including 2.11.1 are affected. Users may need to manually apply the patch.

Published: 2022-01-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-41141 is rated Moderate Risk (52.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.62%). Mandatory action: Review affected assets and schedule remediation.

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-2021-41141

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 2025-11-25 1.35% 1.62% +0.27%
2 2025-11-21 1.09% 1.35% +0.26%
3 2025-11-18 1.09%

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41141

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
10.0 6.9 [email protected]

Weakness enumeration for CVE-2021-41141

OS Trackers for CVE-2021-41141

vendor priority summary link
alpine high CVE-2021-41141: 1 source package rows (pjproject); 7 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2021-41141
gentoo normal CVE-2021-41141: 1 GLSA(s) (202210-37), 1 atom(s) (net-libs/pjproject); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-41141
ubuntu low CVE-2021-41141 low priority: Ubuntu including 1 source packages (ring), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 6, ignored 6, needs-triage 3. https://ubuntu.com/security/CVE-2021-41141

Affected software / configurations for CVE-2021-41141

Vendor Product Version Raw CPE
teluu pjsip <= 2.11.1 cpe:2.3:a:teluu:pjsip:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2021-41141

cvelogic Threat Intelligence