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 version 1.10.11, when handling DTLS-SRTP for media setup, FreeSWITCH is susceptible to Denial of Service due to a race condition in the hello handshake phase of the DTLS protocol. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack. If an attacker manages to send a ClientHello DTLS message with an invalid CipherSuite (such as `TLS_NULL_WITH_NULL_NULL`) to the port on the FreeSWITCH server that is expecting packets from the caller, a DTLS error is generated. This results in the media session being torn down, which is followed by teardown at signaling (SIP) level too. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable FreeSWITCH servers for calls that rely on DTLS-SRTP. To address this vulnerability, upgrade FreeSWITCH to 1.10.11 which includes the security fix. The solution implemented is to drop all packets from addresses that have not been validated by an ICE check.
History

Tue, 04 Nov 2025 19:30:00 +0000


Thu, 13 Feb 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2023-12-27T16:30:48.425Z

Updated: 2025-11-04T18:21:32.334Z

Reserved: 2023-12-19T13:52:41.787Z

Link: CVE-2023-51443

cve-icon Vulnrichment

Updated: 2025-11-04T18:21:32.334Z

cve-icon NVD

Status : Modified

Published: 2023-12-27T17:15:08.093

Modified: 2025-11-04T19:16:21.660

Link: CVE-2023-51443

cve-icon Redhat

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