CVE-2023-37457

Asterisk is an open source private branch exchange and telephony toolkit.
In Asterisk versions 18.20.0 and prior, 20.5.0 and prior, and 21.0.0; as
well as ceritifed-asterisk 18.9-cert5 and prior, the ‘update’ functionality
of the PJSIP_HEADER dialplan function can exceed the available buffer space
for storing the new value of a header. By doing so this can overwrite
memory or cause a crash. This is not externally exploitable, unless
dialplan is explicitly written to update a header based on data from an
outside source. If the ‘update’ functionality is not used the vulnerability
does not occur. A patch is available at commit
a1ca0268254374b515fa5992f01340f7717113fa.