A heap-buffer overflow was found in the way libxml2 decoded certain XML entitites. A remote attacker could provide a specially-crafted XML file, which once opened in an application linked against libxml would cause that application to crash, or, potentially, execute arbitrary code with the privileges of the user running the application.

Reference: http://googlechromereleases.blogspot.in/2012/11/stable-channel-update.html

Patch: http://git.gnome.org/browse/libxml2/commit/?id=6a36fbe3b3e001a8a840b5c1fdd81cefc9947f0d

A denial of service flaw was found in the way libxml2, a library providing support to read, modify and write XML and HTML files, performed string substitutions when entity values for external entity references replacement (--noent option) was requested / enabled during the XML file parsing. A remote attacker could provide a specially-crafted XML file containing an external entity expansion, when processed would lead to excessive CPU consumption (denial of service).

This a different flaw from CVE-2013-0338.

Upstream patch:

http://git.gnome.org/browse/libxml2/commit/?id=23f05e0c33987d6605387b300c4be5da2120a7ab

Daniel Veillard discovered that a specially crafted document can lead to a recursive evaluation of entities, the result being an exhaustion of memory and CPU usage

Acknowledgements:

Red Hat would like to thank Andreas Solberg for responsibly disclosing this issue.

Multiple use-after-free vulnerabilities in libxml2 2.5.10, 2.6.16, 2.6.26, 2.6.27, and 2.6.32, and libxml 1.8.17, allow context-dependent attackers to cause a denial of service (application crash) via crafted (1) Notation or (2) Enumeration attribute types in an XML file, as demonstrated by the Codenomicon XML fuzzing framework.

libxml2 before 2.8.0 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted XML data.

IssueDescription:

A denial of service flaw was found in libxml2, a library providing support to read, modify and write XML and HTML files. A remote attacker could provide a specially crafted XML file that, when processed by an application using libxml2, would lead to excessive CPU consumption (denial of service) based on excessive entity substitutions, even if entity substitution was disabled, which is the parser default behavior.

A denial of service flaw was found in the way libxml2, a library providing support to read, modify and write XML and HTML files, performed string substitutions when entity values for entity references replacement (--noent option) was requested / enabled during the XML file parsing. A remote attacker could provide a specially-crafted XML file that, when processed would lead to excessive CPU consumption (denial of service).

A stack overflow flaw was found in libxml by parsing root XML document element DTD definition. Providing a specially-crafted XML file would lead to excessive stack growth and denial of service (application crash), when opened by a victim.