FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary…

Why it is Yellow

• CVSS 8.2 high
• Remotely exploitable without logging in

References

• https://github.com/signalwire/freeswitch/commit/b999d2a594f025ac0dd4d7b137635308ef298272
• https://github.com/signalwire/freeswitch/releases/tag/v1.11.2
• https://github.com/signalwire/freeswitch/security/advisories/GHSA-mjp3-3cq2-hxj4

Original description

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, udptl_rx_packet() used a peer-controlled FEC entry count directly to fill five-entry FEC arrays in a mod_spandsp T.38 session. A larger count wrote sender-controlled error-recovery data beyond those arrays and persisted the oversized count for a later reconstruction pass. Any peer able to deliver UDPTL to an established T.38 fax session can reach the parser, including deployments using fax applications or a T.38 gateway. The memory corruption can crash FreeSWITCH and end every active call, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.