CVE-2023-34241

OpenPrinting CUPS is a standards-based, open source printing system for
Linux and other Unix-like operating systems. Starting in version 2.0.0 and
prior to version 2.4.6, CUPS logs data of free memory to the logging
service AFTER the connection has been closed, when it should have logged
the data right before. This is a use-after-free bug that impacts the entire
cupsd process. The exact cause of this issue is the function
httpClose(con->http) being called in scheduler/client.c. The problem is
that httpClose always, provided its argument is not null, frees the pointer
at the end of the call, only for cupsdLogClient to pass the pointer to
httpGetHostname. This issue happens in function cupsdAcceptClient if
LogLevel is warn or higher and in two scenarios: there is a double-lookup
for the IP Address (HostNameLookups Double is set in cupsd.conf) which
fails to resolve, or if CUPS is compiled with TCP wrappers and the
connection is refused by rules from /etc/hosts.allow and
/etc/hosts.deny. Version 2.4.6 has a patch for this issue.