Fix CVE-2022-2309: NULL Pointer Dereference allows attackers to cause a
denial of service (or application crash). This only applies when lxml is
used together with libxml2 2.9.10 through 2.9.14. libxml2 2.9.9 and
earlier are not affected. It allows triggering crashes through forged
input data, given a vulnerable code sequence in the application. The
vulnerability is caused by the iterwalk function (also used by the
canonicalize function). Such code shouldn't be in wide-spread use, given
that parsing + iterwalk would usually be replaced with the more
efficient iterparse function. However, an XML converter that serialises
to C14N would also be vulnerable, for example, and there are legitimate
use cases for this code sequence. If untrusted input is received (also
remotely) and processed via iterwalk function, a crash can be
triggered.
https://github.com/lxml/lxml/blob/lxml-4.9.1/CHANGES.txt
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
ff3b5ca2c1