CVE-2021-3537: Null Pointer Dereference
A NULL pointer dereference flaw was found in libxml2, where it did not propagate errors while parsing XML mixed content. This flaw causes the application to crash if an untrusted XML document is parsed in recovery mode and post validated. The highest threat from this vulnerability is to system availability.
Other sources
A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixed content, causing a NULL dereference. If an untrusted XML document was parsed in recovery mode and post-validated, the flaw could be used to crash the application. The highest threat from this vulnerability is to system availability.
GNOME libxml2 is vulnerable to a denial of service, caused by a NULL pointer dereference flaw when parsing XML mixed content in recovery mode and post-validated. A remote attacker could exploit this vulnerability to cause the application to crash.
— IBM
Parsing specially crafted Mixed Content while parsing XML data may lead to invalid data structure being created, as errors were not propagated. This could lead to several NULL Pointer Dereference when post-validating documents parsed in recovery mode.
References:
https://gitlab.gnome.org/GNOME/libxml2/-/issues/243 https://gitlab.gnome.org/GNOME/libxml2/-/issues/244 https://gitlab.gnome.org/GNOME/libxml2/-/issues/245
Upstream fix:
https://gitlab.gnome.org/GNOME/libxml2/-/commit/babe75030c7f64a37826bb3342317134568bef61
— Red Hat
Affected Software
Remediation
Patch Available
Patch Available
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the vulnerability ID for this flaw?
The vulnerability ID for this flaw is CVE-2021-3537.
What is the severity of CVE-2021-3537?
The severity of CVE-2021-3537 is high, with a severity value of 7.
How does CVE-2021-3537 affect libxml2?
CVE-2021-3537 affects libxml2 versions before 2.9.11 by causing a NULL pointer dereference while parsing XML mixed content.
How can an attacker exploit CVE-2021-3537?
An attacker can exploit CVE-2021-3537 by providing an untrusted XML document in recovery mode and post-validation, which can crash the application.
Is there a fix for CVE-2021-3537?
Yes, the fix for CVE-2021-3537 is to update to libxml2 version 2.9.11 or newer.