CVE-2021-43804

highpriority · track · 30EPSS 0.023 · 83 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

2.29% (83rd) EPSS

CVSS 7.5 · high

Is it mine?

9 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.7–7.5

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.17.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Lprimary · NVD / NIST USexploitability 3.9 · impact 3.4

v3.17.3highAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Lsecondary · FSTEC (BDU) RU

v3.17.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Lsecondary · ENISA EU

v3.17.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Lsecondary · security-advisories@github.comexploitability 3.9 · impact 3.4

v3.16.7mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125USprimaryCWE-125US

affected products (9)

Products and version ranges known to be affected.

pjsip pjproject≤ ≤ 2.11.1enisa_euvdEU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 2.10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 11fstec_bduRU
Сообщество свободного программного обеспечения PJSIP≤ 2.11.1fstec_bduRU
debian debian linux= 10.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
teluu pjsip≤ 2.11.1nvdUScpe:2.3:a:teluu:pjsip:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-12-22modified 2026-06-17

related (11,872)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-11645US	—OT critical	2.44% (84th)	KEV	2026-06-09
Out of bounds read and write in V8 in Google Chrome prior to 149.0.7827.103 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium…
CVE-2026-3055US	critical9.8OT critical	91.5% (100th)	KEV	2026-03-23
Insufficient input validation in NetScaler ADC and NetScaler Gateway when configured as a SAML IDP leading to memory overread
CVE-2025-5777US	high7.5OT critical	100.0% (100th)	KEV	2025-06-17
Insufficient input validation leading to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server
CVE-2025-5419US	—OT critical	7.82% (95th)	KEV	2025-06-03
Out of bounds read and write in V8 in Google Chrome prior to 137.0.7151.68 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium secur…
CVE-2025-24991US	—OT critical	2.02% (81st)	KEV	2025-03-11
Out-of-bounds read in Windows NTFS allows an authorized attacker to disclose information locally.

+11867 more

references (29)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan