Ubuntu 21.10 USN-5225-1: Lxml Critical Arbitrary Code Execution

ubuntu

January 12, 2022

lxml could be made to execute arbitrary code if it received a specially crafted XML or HTML file.

Summary

lxml could be made to execute arbitrary code if it received a specially crafted XML

or HTML file.

Software Description:

- lxml: pythonic binding for the libxml2 and libxslt libraries

Details:

It was discovered that lxml incorrectly handled certain XML and HTML files.

An attacker could possibly use this issue to execute arbitrary code.

Topics Covered

security advisory code execution Ubuntu arbitrary code XML lxml HTML

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 21.10:
  python3-lxml                    4.6.3+dfsg-0.1ubuntu0.2

Ubuntu 21.04:
  python3-lxml                    4.6.3-1ubuntu0.2

Ubuntu 20.04 LTS:
  python-lxml                     4.5.0-1ubuntu0.5
  python3-lxml                    4.5.0-1ubuntu0.5

Ubuntu 18.04 LTS:
  python-lxml                     4.2.1-1ubuntu0.6
  python3-lxml                    4.2.1-1ubuntu0.6

Ubuntu 16.04 ESM:
  python-lxml                     3.5.0-1ubuntu0.4+esm2
  python3-lxml                    3.5.0-1ubuntu0.4+esm2

Ubuntu 14.04 ESM:
  python-lxml                     3.3.3-1ubuntu0.2+esm5
  python3-lxml                    3.3.3-1ubuntu0.2+esm5

In general, a standard system update will make all the necessary changes.