Amazon Linux 2 Security Advisory: ALAS-2023-1956
Advisory Release Date: 2023-02-17 00:12 Pacific
Advisory Updated Date: 2025-02-11 23:16 Pacific
2025-02-11: CVE-2018-19787 was added to this advisory.
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. (CVE-2018-19787)
There's a flaw in python-lxml's HTML Cleaner component, which is responsible for sanitizing HTML and Javascript. An attacker who is able to submit a crafted payload to a web service using python-lxml's HTML Cleaner may be able to trigger script execution in clients such as web browsers. This can occur because the HTML Cleaner did not remove scripts within SVG images in data URLs such as <img src=>. XSS can result in impacts to the integrity and availability of the web page, as well as a potential impact to data confidentiality in some circumstances. (CVE-2021-43818)
Affected Packages:
python-lxml
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update python-lxml to update your system.
aarch64:
python-lxml-3.2.1-4.amzn2.0.4.aarch64
python-lxml-debuginfo-3.2.1-4.amzn2.0.4.aarch64
i686:
python-lxml-3.2.1-4.amzn2.0.4.i686
python-lxml-debuginfo-3.2.1-4.amzn2.0.4.i686
noarch:
python-lxml-docs-3.2.1-4.amzn2.0.4.noarch
src:
python-lxml-3.2.1-4.amzn2.0.4.src
x86_64:
python-lxml-3.2.1-4.amzn2.0.4.x86_64
python-lxml-debuginfo-3.2.1-4.amzn2.0.4.x86_64