The Qualys Research Labs discovered several vulnerabilities in the GNU C
Library’s __vsyslog_internal() function (called by syslog() and
vsyslog()). A heap-based buffer overflow (CVE-2023-6246), an off-by-one
heap overflow (CVE-2023-6779) and an integer overflow (CVE-2023-6780)
can be exploited for privilege escalation or denial of service.
Details can be found in the Qualys advisory at
https://www.qualys.com/2024/01/30/syslog
Additionally a memory corruption was discovered in the glibc’s qsort()
function, due to missing bounds check and when called by a program
with a non-transitive comparison function and a large number of
attacker-controlled elements. As the use of qsort() with a
non-transitive comparison function is undefined according to POSIX and
ISO C standards, this is not considered a vulnerability in the glibc
itself. However the qsort() implementation was hardened against
misbehaving callers.
Details can be found in the Qualys advisory at
https://www.qualys.com/2024/01/30/qsort
https://security-tracker.debian.org/tracker/DSA-5611-1
