Stefan Behnel

5 exploits Active since Dec 2018
CVE-2021-43818 WRITEUP HIGH WRITEUP
lxml < 4.6.5 - Cross-Site Scripting via HTML Cleaner Bypass
lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch. There are no known workarounds available.
CVSS 8.2
CVE-2021-43818 WRITEUP HIGH WRITEUP
lxml < 4.6.5 - Cross-Site Scripting via HTML Cleaner Bypass
lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch. There are no known workarounds available.
CVSS 8.2
CVE-2018-19787 WRITEUP MEDIUM WRITEUP
lxml < 4.2.5 - Cross-Site Scripting via Escaped JavaScript URLs
An issue was discovered in lxml before 4.2.5. lxml/html/clean.py in the lxml.html.clean module does not remove javascript: URLs that use escaping, allowing a remote attacker to conduct XSS attacks, as demonstrated by "j a v a s c r i p t:" in Internet Explorer. This is a similar issue to CVE-2014-3146.
CVSS 6.1
CVE-2021-28957 WRITEUP MEDIUM WRITEUP
lxml < 4.6.3 - Cross-Site Scripting via Formaction Attribute Bypass
An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safe_attrs_only and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3.
CVSS 6.1
CVE-2022-2309 WRITEUP HIGH WRITEUP
lxml < 4.9.1 - Denial of Service via iterwalk Function
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.
CVSS 7.5