Pion Interceptor's improper RTP padding handling allows remote crash for SFU users (DoS)
### Impact Pion Interceptor versions v0.1.36 through v0.1.38 contain a bug in a RTP packet factory that can be exploited to trigger a panic with Pion based SFU via crafted RTP packets, This only affect users that use pion/interceptor. ### Patches Upgrade to v0.1.39 or later, which includes PR [#338](https://github.com/pion/interceptor/pull/338) which validates that: `padLen > 0 && padLen <= payloadLength` and return error on overflow, avoiding panic. If upgrading is not possible, apply the patch from the pull request manually or drop packets whose P-bit is set but whose padLen is zero or larger than the remaining payload. ### Workarounds At the application layer, reject any RTP packet where: ``` hasPadding (P-bit field) == true && (padLen == 0 || padLen > packetLen – headerLen) ``` before passing it to Pion’s packet factories. ### References Commit fixing the bug: https://github.com/pion/interceptor/commit/fa5b35ea867389cec33a9c82fffbd459ca8958e5 Pull request: https://github.com/pion/interceptor/pull/338 Issue: https://github.com/pion/webrtc/issues/3148
02 / AFFECTED SOFTWARE
Affected packages
3 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Pion Interceptor is a framework for building RTP/RTCP communication software. Versions v0.1.36 through v0.1.38 contain a bug in a RTP packet factory that can be exploited to trigger a panic with Pion based SFU via crafted RTP packets, This only affect users that use pion/interceptor. Users should upgrade to v0.1.39 or later, which validates that: `padLen > 0 && padLen <= payloadLength` and return error on overflow, avoiding panic. If upgrading is not possible, apply the patch from the pull request manually or drop packets whose P-bit is set but whose padLen is zero or larger than the remaining payload.
### Impact Pion Interceptor versions v0.1.36 through v0.1.38 contain a bug in a RTP packet factory that can be exploited to trigger a panic with Pion based SFU via crafted RTP packets, This only affect users that use pion/interceptor. ### Patches Upgrade to v0.1.39 or later, which includes PR [#338](https://github.com/pion/interceptor/pull/338) which validates that: `padLen > 0 && padLen <= payloadLength` and return error on overflow, avoiding panic. If upgrading is not possible, apply the patch from the pull request manually or drop packets whose P-bit is set but whose padLen is zero or larger than the remaining payload. ### Workarounds At the application layer, reject any RTP packet where: ``` hasPadding (P-bit field) == true && (padLen == 0 || padLen > packetLen – headerLen) ``` before passing it to Pion’s packet factories. ### References Commit fixing the bug: https://github.com/pion/interceptor/commit/fa5b35ea867389cec33a9c82fffbd459ca8958e5 Pull request: https://github.com/pion/interceptor/pull/338 Issue: https://github.com/pion/webrtc/issues/3148
Pion Interceptor's improper RTP padding handling allows remote crash for SFU users (DoS) in github.com/pion/interceptor
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/49xxx/CVE-2025-49140.json
- https://github.com/pion/interceptor/commit/fa5b35ea867389cec33a9c82fffbd459ca8958e5
- https://github.com/pion/interceptor/pull/338
- https://github.com/pion/interceptor/security/advisories/GHSA-f26w-gh5m-qq77
- https://github.com/pion/webrtc/issues/3148
- https://nvd.nist.gov/vuln/detail/CVE-2025-49140
- https://github.com/pion/interceptor