🛡️ CVE-2021-43845 on Debian — asterisk

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

PJSIP is a free and open source multimedia communication library. In version 2.11.1 and prior, if incoming RTCP XR message contain block, the data field is not checked against the received packet size, potentially resulting in an out-of-bound read access. This affects all users that use PJMEDIA and RTCP XR. A malicious actor can send a RTCP XR message with an invalid packet size.

Distribution advisory

This page covers CVE-2021-43845 as tracked by Debian, for the package asterisk. The fix is available in version 1:18.12.0~dfsg+~cs6.12.40431413-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability high.

Affected software

DEBIAN-CVE-2021-43845 is recorded against 2 packages.

asterisk (fixed in 1:18.12.0~dfsg+~cs6.12.40431413-1)
ring (fixed in 20230206.0~ds1-1)

Timeline and source

Published on 27 December 2021 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-43845 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Alpine Ubuntu

Details

Severity Unknown

CVSS Score N/A

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2021-12-27

Updated 2026-08-12

Modified 2026-08-04

Fix URL N/A

Affected Packages

Software	From version	Fixed in
asterisk	—	1:18.12.0~dfsg+~cs6.12.40431413-1
ring	—	20230206.0~ds1-1

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2021-43845

🔗 NVD 🔗 Mitre

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