CVE-2021-43804
Out-of-bounds read when parsing RTCP BYE message in PJSIP
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
7.3
Out-of-bounds read when parsing RTCP BYE message in PJSIP
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.
- Record
CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2021-30695
7.3
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.
- Record
EUVD-2021-30695- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
NVD
7.3
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.
- Record
CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-125
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-43804
7.3
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.
- Record
ALPINE-CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
OSV
7.3
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.
- Record
CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-43804
7.3
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.
- Record
DEBIAN-CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-43804
7.3
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.
- Record
UBUNTU-CVE-2021-43804- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
OSVUSN-6422-1 No score
ring vulnerabilities
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to execute arbitrary code. (CVE-2021-37706)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2021-43299, CVE-2021-43300, CVE-2021-43301, CVE-2021-43302, CVE-2021-43303, CVE-2021-43804, CVE-2021-43845, CVE-2022-21723, CVE-2022-23537, CVE-2022-23547, CVE-2022-23608, CVE-2022-24754, CVE-2022-24763, CVE-2022-24764, CVE-2022-24793, CVE-2022-31031, CVE-2022-39244)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2022-21722)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2023-27585)
- Record
USN-6422-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pjprojectAlpine:v3.16 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.17 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.18 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.19 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.20 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.21 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.22 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.23 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.24 |
before 2.12-r0 | 2.12-r0 |
asteriskDebian:14 |
before 1:18.12.0~dfsg+~cs6.12.40431413-1, plus listed versions 0.1.11-30.1.11-3woody11:1.0.5-21:1.0.5-41:1.0.6-1 Show 45 moreShow less1:1.0.6-21:1.0.7-11:1.0.7.dfsg.1-11:1.0.7.dfsg.1-21:1.0.7.dfsg.1-2sarge11:1.0.7.dfsg.1-2sarge21:1.0.7.dfsg.1-2sarge31:1.0.7.dfsg.1-2sarge41:1.0.7.dfsg.1-2sarge51:1.0.7.dfsg.1-2sarge61:1.0.9.dfsg-11:1.0.9.dfsg-31:1.0.9.dfsg-41:1.0.9.dfsg-51:1.0.9.dfsg-61:1.2.0-beta1.dfsg-11:1.2.0-beta2.dfsg-11:1.2.0-beta2.dfsg-21:1.2.0-beta2.dfsg-31:1.2.0-rc1.dfsg-11:1.2.0-rc2.dfsg-11:1.2.0.dfsg-11:1.2.0.dfsg-21:1.2.0.dfsg-31:1.2.0.dfsg-41:1.2.0.dfsg-51:1.2.0.dfsg-61:1.2.1.dfsg-11:1.2.1.dfsg-21:1.2.1.dfsg-31:1.2.10.dfsg-11:1.2.10.dfsg-1bpo11:1.2.10.dfsg-21:1.2.10.dfsg-31:1.2.11.dfsg-11:1.2.12.1.dfsg-11:1.2.13~dfsg-11:1.2.13~dfsg-21:1.2.13~dfsg-2etch11:1.2.13~dfsg-2etch21:1.2.13~dfsg-2etch31:1.2.13~dfsg-2etch41:1.2.14~dfsg-11:1.2.14~dfsg-21:1.2.14~dfsg-3 |
1:18.12.0~dfsg+~cs6.12.40431413-1 |
Show 12 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ringDebian:12 |
before 20230206.0~ds1-1 | 20230206.0~ds1-1 |
pjprojectDebian:9 From an advisory covering 15 CVEs |
before 2.5.5~dfsg-6+deb9u3, plus listed versions 2.5.5~dfsg-62.5.5~dfsg-6+deb9u12.5.5~dfsg-6+deb9u2 |
2.5.5~dfsg-6+deb9u3 |
asteriskDebian:10 From an advisory covering 20 CVEs |
before 1:16.28.0~dfsg-0+deb10u1, plus listed versions 1:16.10.0~dfsg-11:16.12.0~dfsg-11:16.15.0~dfsg-11:16.15.1~dfsg-11:16.16.1~dfsg+~2.10-1 Show 14 moreShow less1:16.16.1~dfsg+~2.10-21:16.16.1~dfsg-11:16.16.1~dfsg-1~bpo10+11:16.16.1~dfsg-21:16.16.1~dfsg-31:16.16.1~dfsg-41:16.2.1~dfsg-11:16.2.1~dfsg-1+deb10u11:16.2.1~dfsg-1+deb10u21:16.2.1~dfsg-21:16.23.0~dfsg+~2.10-11:16.23.0~dfsg+~cs6.10.20220309-11:16.23.0~dfsg+~cs6.10.20220309-21:16.23.0~dfsg+~cs6.10.40431411-1 |
1:16.28.0~dfsg-0+deb10u1 |
ringDebian:10 From an advisory covering 20 CVEs |
before 20190215.1.f152c98~ds1-1+deb10u2, plus listed versions 20190215.1.f152c98~ds1-120190215.1.f152c98~ds1-1+deb10u1 |
20190215.1.f152c98~ds1-1+deb10u2 |
ringDebian:11 From an advisory covering 21 CVEs |
before 20210112.2.b757bac~ds1-1+deb11u1, plus listed versions 20210112.2.b757bac~ds1-1 |
20210112.2.b757bac~ds1-1+deb11u1 |
asteriskDebian:11 From an advisory covering 20 CVEs |
before 1:16.28.0~dfsg-0+deb11u1, plus listed versions 1:16.16.1~dfsg+~2.10-11:16.16.1~dfsg+~2.10-21:16.16.1~dfsg-11:16.16.1~dfsg-1+deb11u11:16.16.1~dfsg-1+deb11u1~bpo10+1 Show 7 moreShow less1:16.16.1~dfsg-21:16.16.1~dfsg-31:16.16.1~dfsg-41:16.23.0~dfsg+~2.10-11:16.23.0~dfsg+~cs6.10.20220309-11:16.23.0~dfsg+~cs6.10.20220309-21:16.23.0~dfsg+~cs6.10.40431411-1 |
1:16.28.0~dfsg-0+deb11u1 |
pjprojectUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2.1.0.0.ast20130823-12.1.0.0.ast20130823-1+deb8u1build0.16.04.12.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1 |
None known |
pjprojectUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.6~dfsg-22.7~dfsg-12.7.1~dfsg-12.7.1~dfsg-1build12.7.2~dfsg-12.7.2~dfsg-1ubuntu0.1~esm1 |
None known |
ringUbuntu:Pro:18.04:LTS |
before 20180228.1.503da2b~ds1-1ubuntu0.1~esm1, plus listed versions 20170803.2.5fcfe3f~dfsg1-120171024.1.eadbdeb~ds1-120171129.2.cf5bbff~ds1-120171129.2.cf5bbff~ds1-220180119.1.9e06f94~ds1-1 Show 4 moreShow less20180119.1.9e06f94~ds1-320180222.1.7bffde2~ds2-220180228.1.503da2b~ds1-120180228.1.503da2b~ds1-1build1 |
20180228.1.503da2b~ds1-1ubuntu0.1~esm1 |
ringUbuntu:20.04:LTS |
before 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1, plus listed versions 20190215.1.f152c98~ds1-120190215.1.f152c98~ds1-1build120190215.1.f152c98~ds1-1build2 |
20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 |
ringUbuntu:Pro:18.04:LTS From an advisory covering 20 CVEs |
before 20180228.1.503da2b~ds1-1ubuntu0.1~esm1, plus listed versions 20170803.2.5fcfe3f~dfsg1-120171024.1.eadbdeb~ds1-120171129.2.cf5bbff~ds1-120171129.2.cf5bbff~ds1-220180119.1.9e06f94~ds1-1 Show 4 moreShow less20180119.1.9e06f94~ds1-320180222.1.7bffde2~ds2-220180228.1.503da2b~ds1-120180228.1.503da2b~ds1-1build1 |
20180228.1.503da2b~ds1-1ubuntu0.1~esm1 |
ringUbuntu:20.04:LTS From an advisory covering 20 CVEs |
before 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1, plus listed versions 20190215.1.f152c98~ds1-120190215.1.f152c98~ds1-1build120190215.1.f152c98~ds1-1build2 |
20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43804 is a high vulnerability (CVSS 7.3) in Teluu Pjsip, published December 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.29%, the 83rd percentile. Fixed in pjproject 2.12-r0.
References
github.com/pjsip/pjproject/security/advisories/GHSA-3qx3-cg72-wrh9
github.com/pjsip/pjproject/commit/8b621f192cae14456ee0b0ade52ce6c6f258af1e
lists.debian.org/debian-lts-announce/2022/03/msg00035.html
security.gentoo.org/glsa/202210-37
lists.debian.org/debian-lts-announce/2022/11/msg00021.html
debian.org/security/2022/dsa-5285
Show 26 moreShow less
lists.debian.org/debian-lts-announce/2023/08/msg00038.html
lists.debian.org/debian-lts-announce/2024/09/msg00030.html
security.alpinelinux.org/vuln/CVE-2021-43804
security-tracker.debian.org/tracker/CVE-2021-43804
ubuntu.com/security/CVE-2021-43804
ubuntu.com/security/notices/USN-6422-1
cve.org/CVERecord?id=CVE-2021-43804
ubuntu.com/security/CVE-2021-37706
ubuntu.com/security/CVE-2021-43299
ubuntu.com/security/CVE-2021-43300
ubuntu.com/security/CVE-2021-43301
ubuntu.com/security/CVE-2021-43302
ubuntu.com/security/CVE-2021-43303
ubuntu.com/security/CVE-2021-43845
ubuntu.com/security/CVE-2022-21722
ubuntu.com/security/CVE-2022-21723
ubuntu.com/security/CVE-2022-23537
ubuntu.com/security/CVE-2022-23547
ubuntu.com/security/CVE-2022-23608
ubuntu.com/security/CVE-2022-24754
ubuntu.com/security/CVE-2022-24763
ubuntu.com/security/CVE-2022-24764
ubuntu.com/security/CVE-2022-24793
ubuntu.com/security/CVE-2022-31031
ubuntu.com/security/CVE-2022-39244
ubuntu.com/security/CVE-2023-27585
Left out here: 203 versions. The JSON record has them.