CVE-2023-27601

Date: March 15, 2023

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Prior to versions 3.1.7 and 3.2.4, OpenSIPS crashes when a malformed SDP body is received and is processed by the "delete_sdp_line" function in the sipmsgops module. This issue can be reproduced by calling the function with an SDP body that does not terminate by a line feed (i.e. "\n"). The vulnerability was found while performing black-box fuzzing against an OpenSIPS server running a configuration that made use of the functions "codec_delete_except_re" and "codec_delete_re". The same issue was also discovered while performing coverage guided fuzzing on the function "codec_delete_except_re". The crash happens because the function "delete_sdp_line" expects that an SDP line is terminated by a line feed ("\n"): By abusing this vulnerability, an attacker is able to crash the server. It affects configurations containing functions that rely on the affected code, such as the function "codec_delete_except_re". Due to the sanity check that is performed in the "del_lump" function, exploitation of this issue will generate an "abort" in the lumps processing function, resulting in a Denial of Service. This issue has been fixed in versions 3.1.7 and 3.2.4.

Language: C