CVE-2021-43818

Advisory

Lxml 4.6.5 includes a fix for CVE-2021-43818: 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 the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch.

Affected package

Affected versions

Fixed versions

Vulnerability changelog

==================

Bugs fixed
----------

* A vulnerability (GHSL-2021-1038) in the HTML cleaner allowed sneaking script
content through SVG images.

* A vulnerability (GHSL-2021-1037) in the HTML cleaner allowed sneaking script
content through CSS imports and other crafted constructs.

Resources

• https://pypi.org/project/lxml
• https://pyup.io/changelogs/lxml/
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43818
• https://github.com/lxml/lxml/commit/f2330237440df7e8f39c3ad1b1aa8852be3b27c0
• https://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec29fb7d090a4b1712a9c#diff-59130575b4fb2932c957db2922977d7d89afb0b2085357db1a14615a2fcad776
• https://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8
• https://github.com/lxml/lxml/commit/12fa9669007180a7bb87d990c375cf91ca5b664a
• https://lists.fedoraproject.org/archives/list/[email protected]/message/WZGNET2A4WGLSUXLBFYKNC5PXHQMI3I7/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/ZQ4SPKJX3RRJK4UWA6FXCRHD2TVRQI44/
• https://lists.debian.org/debian-lts-announce/2021/12/msg00037.html
• https://security.netapp.com/advisory/ntap-20220107-0005/
• https://www.debian.org/security/2022/dsa-5043
• https://lists.fedoraproject.org/archives/list/[email protected]/message/TUIS2KE3HZ2AAQKXFLTJFZPP2IFHJTC7/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/V2XMOM5PFT6U5AAXY6EFNT5JZCKKHK2V/
• https://www.oracle.com/security-alerts/cpuapr2022.html
• https://www.oracle.com/security-alerts/cpujul2022.html
• https://security.gentoo.org/glsa/202208-06