Medium: python-lxml

Issue Overview:

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. (CVE-2021-28957)

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.

New Packages:

aarch64:  
    python-lxml-3.2.1-4.amzn2.0.6.aarch64  
    python3-lxml-3.2.1-4.amzn2.0.6.aarch64  
    python-lxml-debuginfo-3.2.1-4.amzn2.0.6.aarch64  
  
i686:  
    python-lxml-3.2.1-4.amzn2.0.6.i686  
    python3-lxml-3.2.1-4.amzn2.0.6.i686  
    python-lxml-debuginfo-3.2.1-4.amzn2.0.6.i686  
  
noarch:  
    python-lxml-docs-3.2.1-4.amzn2.0.6.noarch  
  
src:  
    python-lxml-3.2.1-4.amzn2.0.6.src  
  
x86_64:  
    python-lxml-3.2.1-4.amzn2.0.6.x86_64  
    python3-lxml-3.2.1-4.amzn2.0.6.x86_64  
    python-lxml-debuginfo-3.2.1-4.amzn2.0.6.x86_64  

Additional References

Red Hat: CVE-2021-28957

Mitre: CVE-2021-28957