Out-of-bounds read when parsing RTCP BYE message in PJSIP
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| pjsip | pjproject | up to 2.11.1 | — | No fix listed | CNA |
- pjproject Vendorpjsip Affected up to 2.11.1 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-43804
References
Patch 2
Advisory 4
More pjsip vulnerabilities
- TI-2022-13076 Potential stack buffer overflow when parsing message as a STUN client CVSS 3.1CRITICAL 9.8
- TI-2022-08599 Potential out-of-bound read/write in PJSIP CVSS 3.1CRITICAL 9.8
- TI-2023-20051 PJSIP has use-after-free vulnerability in SRTP media transport CVSS 3.1CRITICAL 9.8
- TI-2022-06096 Out-of-bounds read in multipart parsing in PJSIP CVSS 3.1CRITICAL 9.1
- TI-2022-07661 Use after free in PJSIP CVSS 3.1CRITICAL 9.8
- TI-2022-06095 Potential out-of-bound read during RTP/RTCP parsing in PJSIP CVSS 3.1CRITICAL 9.1
Sources
- CVE-2021-43804 · CVE Program
- CVE-2021-43804 · NVD
- FIRST EPSS
- CVE-2021-43804 · Red Hat security data · CC BY 4.0
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