Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2022-2309: 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. CVE-2021-43818: 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.
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | python-lxml-debugsource | 0:4.7.1-3.amzn2023.0.1 |
| Amazon Linux · 2023 | python3-lxml | 0:4.7.1-3.amzn2023.0.1 |
| Amazon Linux · 2023 | python3-lxml-debuginfo | 0:4.7.1-3.amzn2023.0.1 |
Vulnerabilities 2
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High 8.2
HTML Cleaner allows crafted and SVG embedded scripts to pass through
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 th…
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Medium 5.3
NULL Pointer Dereference in lxml/lxml
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 fo…