QID 354846

Date Published: 2023-03-23

QID 354846: Amazon Linux Security Advisory for python-lxml : ALAS-2023-1709

A cross-site scripting (xss) vulnerability was found in the python-lxml's clean module.
The module's parser did not properly imitate browsers, causing different behaviors between the sanitizer and the user's page.
This flaw allows a remote attacker to run arbitrary html/js code.
The highest threat from this vulnerability is to confidentiality and integrity. (
( CVE-2020-27783) 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)



Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

Successful exploitation of this vulnerability could lead to a securitybreach or could affect integrity, availability, and confidentiality.

  • CVSS V3 rated as High - 7.1 severity.
  • CVSS V2 rated as High - 6.8 severity.
    • Solution
    Please refer to Amazon advisory: ALAS-2023-1709 for affected packages and patching details, or update with your package manager.
    Vendor References

    CVEs related to QID 354846

    CVE-2020-27783 | CVE-2021-43818 |
    Software Advisories
    Advisory ID Software Component Link
    ALAS-2023-1709 amazon linux URL Logo alas.aws.amazon.com/ALAS-2023-1709.html
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