Debian: DSA-5419-1 Critical: c-ares Buffer Underflow and DoS

CVE-2023-31130

ares_inet_net_pton() is found to be vulnerable to a buffer underflow
for certain ipv6 addresses, in particular "0::00:00:00/2" was found
to cause an issue. c-ares only uses this function internally for
configuration purposes, however external usage for other purposes may
cause more severe issues.

CVE-2023-32067

Target resolver may erroneously interprets a malformed UDP packet
with a lenght of 0 as a graceful shutdown of the connection, which
could cause a denial of service.

For the stable distribution (bullseye), these problems have been fixed in
version 1.17.1-1+deb11u3.

We recommend that you upgrade your c-ares packages.

For the detailed security status of c-ares please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/c-ares

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/