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Debian LTS Advisory DLA-3783-1                debian-lts@lists.debian.org
https://www.debian.org/lts/security/                         Tobias Frost
April 07, 2024                                https://wiki.debian.org/LTS
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Package        : expat
Version        : 2.2.6-2+deb10u7
CVE ID         : CVE-2023-52425
Debian Bug     : 1063238

Expat, an XML parsing C library has been found to have an vulnerability
that allows an attacker to perform a denial of service (resource
consumption, when many full reparsings are required in the case of a
large tokens.

When parsing a really big token that requires multiple buffer fills to
complete, expat has to re-parse the token from start multiple times,
which takes time. These patches introduce a heuristic that, when having
failed on the same token multiple times, defers further parsing until
there's significantly more data available.

The patch also introduces an optiional API,
XML_SetReparseDeferralEnabled(), to disable the new heuristic.

For Debian 10 buster, this problem has been fixed in version
2.2.6-2+deb10u7.

We recommend that you upgrade your expat packages.

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

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