CVE-2026-116567FreeSWITCH: Pre-authentication stack buffer overflow in mod_rtmp control-message handling

Beschreibung

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, rtmp_handle_control() rendered an RTMP user-control message into a 200-byte stack buffer using an unbounded sprintf loop controlled by the wire message length. A body of roughly 70 bytes or more overflowed the stack before any RTMP login, because the handshake authenticates neither side. The flaw affects deployments that build and load mod_rtmp, which is disabled in the stock build and configuration but commonly exposes a listener on TCP port 1935 when enabled. One unauthenticated message can crash FreeSWITCH and end every active call; the constrained ASCII hex output has not yielded control-flow hijacking. This issue is fixed in version 1.11.2.

Daten: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Wiedergegeben wie in der Quelle, auf Englisch.

Betroffene Produkte und Versionen

Referenzen und Patches

• https://github.com/signalwire/freeswitch/security/advisories/GHSA-hj6x-9653-p796 Vendor AdvisoryMitigation
• https://github.com/signalwire/freeswitch/commit/fc0db829b87d1a5a3043e355b4294c41851b13c6 Patch
• https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 Release Notes