SIPSorcery: Malformed UDP datagram crashes TurnServer receive loop with no restart, disabling TURN UDP relay for all clients (DoS)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary TurnServer.ReceiveUdpAsync places its generic catch (Exception) OUTSIDE the while receive loop, and Start() launches the loop fire-and-forget with no supervision or restart. A single pre-authentication UDP datagram whose STUN header first byte is in 0x80–0xFF causes STUNHeader.ParseSTUNHeader to throw ApplicationException, which unwinds past the loop and terminates it. The TURN UDP relay is then dead for ALL clients until the process is restarted. Root Cause src/SIPSorcery/net/TURN/TurnServer.cs: - ReceiveUdpAsync (:555-577): the inner try (:562-567) wraps only udpSocket.ReceiveAsync(); HandleUdpDatagram(result.Buffer, result.RemoteEndPoint) (:569) is inside the while body but OUTSIDE that inner try. The generic catch (Exception ex) (:573) is lexically OUTSIDE the while. - Start() does = ReceiveUdpAsync(); (:381) — fire-and-forget, no restart. - HandleUdpDatagram (:579) calls STUNMessage.ParseSTUNMessage(data, data.Length) (:600) for any non-ChannelData datagram;…

Published by the source

12 Aug 2026, 19:31 UTC

Last modified by the source

12 Aug 2026, 19:45 UTC

Source last checked

26 Oct 2026, 17:05 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-pfvm-w89x-94jw

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-pfvm-w89x-94jw

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# Patch Next advisory brief: GHSA-pfvm-w89x-94jw

Advisory: SIPSorcery: Malformed UDP datagram crashes TurnServer receive loop with no restart, disabling TURN UDP relay for all clients (DoS)
IDs: GHSA-pfvm-w89x-94jw
Record: https://patchnext.com/advisories/ghsa-pfvm-w89x-94jw (revision 2, source checked 26 Oct 2026, 17:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sipsorcery 10.0.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet sipsorcery: affected >= 10.0.5, <= 10.0.13; fixed in 10.0.14

## Suggested inspection (read-only)
- NuGet sipsorcery: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sipsorcery.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-pfvm-w89x-94jw (OSV record GHSA-pfvm-w89x-94jw lists affected ranges: NuGet sipsorcery >=10.0.5 <10.0.14 (fixed))
- Verified: https://github.com/advisories/GHSA-pfvm-w89x-94jw (GitHub-reviewed advisory GHSA-pfvm-w89x-94jw lists affected ranges: NuGet sipsorcery >=10.0.5 <=10.0.13)

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