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Fencer Vulns
high 8.2

CVE-2021-43845 json

Prevent out-of-bounds read in PJSIP

published 2021-12-27 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-30716

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

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.

Patch / fix

  • ring Debian 12 20230206.0~ds1-1
  • asterisk Debian 14 1:18.12.0~dfsg+~cs6.12.40431413-1

debian advisories DEBIAN-CVE-2021-43845

  • ring Ubuntu 20.04 LTS 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1
  • ring Ubuntu Pro 18.04 LTS 20180228.1.503da2b~ds1-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-43845

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • pjproject Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 2.12-r0

alpine advisories ALPINE-CVE-2021-43845

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-43845 updated

pjsip: Multiple vulnerabilities

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.89% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/pjsip/pjproject/pull/2924 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:N/A:P

Affected products

  • pjsip pjproject

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.