Debian 9819 Published by

A c-ares security update has been released for Debian GNU/Linux 10 LTS to address two vulnerabilities.

[SECURITY] [DLA 3471-1] c-ares security update

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Debian LTS Advisory DLA-3471-1 Anton Gladky
June 26, 2023
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Package : c-ares
Version : 1.14.0-1+deb10u3
CVE ID : CVE-2023-31130 CVE-2023-32067

Two vunerabilities were discovered in c-ares, an asynchronous name
resolver library:


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.


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

For Debian 10 buster, these problems have been fixed in version

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:

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: