Arch Linux Security Advisory ASA-202011-15
=========================================
Severity: Medium
Date    : 2020-11-17
CVE-ID  : CVE-2019-20388 CVE-2020-7595 CVE-2020-24977
Package : libxml2
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1263

Summary
======
The package libxml2 before version 2.9.10-6 is vulnerable to multiple
issues including denial of service and information disclosure.

Resolution
=========
Upgrade to 2.9.10-6.

# pacman -Syu "libxml2>=2.9.10-6"

The problems have been fixed upstream but no release is available yet.

Workaround
=========
None.

Description
==========
- CVE-2019-20388 (denial of service)

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 (denial of service)

xmlStringLenDecodeEntities in parser.c in libxml2 2.9.10 has an
infinite loop in a certain end-of-file situation.

- CVE-2020-24977 (information disclosure)

GNOME project libxml2 <= 2.9.10 has a global buffer over-read
vulnerability in xmlEncodeEntitiesInternal at libxml2/entities.c.

Impact
=====
A remote attacker might be able to crash an application using libxml2
or access sensitive information via a crafted XML payload.

References
=========
https://bugs.archlinux.org/task/68510
https://gitlab.gnome.org/GNOME/libxml2/-/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a
https://gitlab.gnome.org/GNOME/libxml2/-/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5
https://gitlab.gnome.org/GNOME/libxml2/-/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2
https://security.archlinux.org/CVE-2019-20388
https://security.archlinux.org/CVE-2020-7595
https://security.archlinux.org/CVE-2020-24977