CVE-2023-27600

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 is patched in versions 3.1.7 and 3.2.4.

Language: C