# CVE-2021-43804: ring: PJSIP is a free and open source multimedia communication library written in C language implementing standard based pr...

CVE-2021-43804 is fixed in 5 products on 1 platform, first by DEBIAN-CVE-2021-43804, released December 22, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-43804
- Priority: High
- CVSS: 7.3 (high)
- EPSS: 0.0229
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 22, 2021

## Description

PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In affected versions if the incoming RTCP BYE message contains a reason's length, this declared length is not checked against the actual received packet size, potentially resulting in an out-of-bound read access. This issue affects all users that use PJMEDIA and RTCP. A malicious actor can send a RTCP BYE message with an invalid reason length. Users are advised to upgrade as soon as possible. There are no known workarounds.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | asterisk Debian 14 | 1:18.12.0~dfsg+~cs6.12.40431413-1 | [DEBIAN-CVE-2021-43804](https://patchblox.com/security/data/fix/linux/debian-cve-2021-43804.md) | Dec 22, 2021 |
| Linux | jami Ubuntu 20.04 LTS (focal) | 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 | [jami 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-jami-20190215.1.f152c98-ds1-1-deb10u2build0.20.04.1.md) | Mar 14, 2023 |
| Linux | jami-daemon Ubuntu 20.04 LTS (focal) | 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 | [jami-daemon 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-jami-daemon-20190215.1.f152c98-ds1-1-deb10u2build0.20.04.1.md) | Mar 14, 2023 |
| Linux | ring Debian 12.15 (bookworm) | 20230206.0~ds1-1 | [DEBIAN-CVE-2021-43804](https://patchblox.com/security/data/fix/linux/debian-cve-2021-43804.md) | Dec 22, 2021 |
| Linux | ring Ubuntu 18.04.6 LTS (bionic) | 20180228.1.503da2b~ds1-1ubuntu0.1~esm1 | [ring 20180228.1.503da2b~ds1-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ring-20180228.1.503da2b-ds1-1ubuntu0.1-esm1.md) | Mar 14, 2023 |
| Linux | ring Ubuntu 20.04 LTS (focal) | 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 | [ring 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ring-20190215.1.f152c98-ds1-1-deb10u2build0.20.04.1.md) | Mar 14, 2023 |
| Linux | ring-daemon Ubuntu 18.04.6 LTS (bionic) | 20180228.1.503da2b~ds1-1ubuntu0.1~esm1 | [ring-daemon 20180228.1.503da2b~ds1-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ring-daemon-20180228.1.503da2b-ds1-1ubuntu0.1-esm1.md) | Mar 14, 2023 |
| Linux | ring-daemon Ubuntu 20.04 LTS (focal) | 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 | [ring-daemon 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ring-daemon-20190215.1.f152c98-ds1-1-deb10u2build0.20.04.1.md) | Mar 14, 2023 |

---

Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.