GHSA-f26w-gh5m-qq77: 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 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