A libxml2 security update has been released for Debian GNU/Linux 9 LTS to address several security vulnerabilities.

DLA 2369-1: libxml2 security update

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Debian LTS Advisory DLA-2369-1 debian-lts@lists.debian.org
  https://www.debian.org/lts/security/ Markus Koschany
September 09, 2020   https://wiki.debian.org/LTS
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Package : libxml2
Version : 2.9.4+dfsg1-2.2+deb9u3
CVE ID : CVE-2017-8872 CVE-2017-18258 CVE-2018-14404
CVE-2018-14567 CVE-2019-19956 CVE-2019-20388
CVE-2020-7595 CVE-2020-24977
Debian Bug : 895245 862450 949583 969529 949582

Several security vulnerabilities were corrected in libxml2, the GNOME
XML library.

CVE-2017-8872

Global buffer-overflow in the htmlParseTryOrFinish function.

CVE-2017-18258

The xz_head function in libxml2 allows remote attackers to cause a
denial of service (memory consumption) via a crafted LZMA file,
because the decoder functionality does not restrict memory usage to
what is required for a legitimate file.

CVE-2018-14404

A NULL pointer dereference vulnerability exists in the
xpath.c:xmlXPathCompOpEval() function of libxml2 when parsing an
invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case.
Applications processing untrusted XSL format inputs may be
vulnerable to a denial of service attack.

CVE-2018-14567

If the option --with-lzma is used, allows remote attackers to cause
a denial of service (infinite loop) via a crafted XML file.

CVE-2019-19956

The xmlParseBalancedChunkMemoryRecover function has a memory leak
related to newDoc->oldNs.

CVE-2019-20388

A memory leak was found in the xmlSchemaValidateStream function of
libxml2. Applications that use this library may be vulnerable to
memory not being freed leading to a denial of service.

CVE-2020-7595

Infinite loop in xmlStringLenDecodeEntities can cause a denial of
service.

CVE-2020-24977

Out-of-bounds read restricted to xmllint --htmlout.

For Debian 9 stretch, these problems have been fixed in version
2.9.4+dfsg1-2.2+deb9u3.

We recommend that you upgrade your libxml2 packages.

For the detailed security status of libxml2 please refer to
its security tracker page at:
  https://security-tracker.debian.org/tracker/libxml2

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