CVE-2023-27598

OpenSIPS is a Session Initiation Protocol (SIP) server implementation.
Prior to versions 3.1.7 and 3.2.4, sending a malformed Via header to
OpenSIPS triggers a segmentation fault when the function calc_tag_suffix
is called. A specially crafted Via header, which is deemed correct by the
parser, will pass uninitialized strings to the function MD5StringArray
which leads to the crash. Abuse of this vulnerability leads to Denial of
Service due to a crash. Since the uninitialized string points to memory
location 0x0, no further exploitation appears to be possible. No special
network privileges are required to perform this attack, as long as the
OpenSIPS configuration makes use of functions such as sl_send_reply or
sl_gen_totag that trigger the vulnerable code. This issue has been fixed
in versions 3.1.7 and 3.2.4.