What’s Vulnerable › Vulnerabilities
CVE-2020-27783
- Severity: medium (CVSS 6.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 4.0% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2020-12-03 · updated 2026-06-17
- Weakness: CWE-79
Description
A XSS vulnerability was discovered in python-lxml's clean module. The module's parser didn't properly imitate browsers, which caused different behaviors between the sanitizer and the user's page. A remote attacker could exploit this flaw to run arbitrary HTML/JS code.
Affected products
- Debian Linux: 9.0, 10.0
- Fedoraproject Fedora: 32, 33
- lxml: from 1.2 before 4.6.2 — fixed in 4.6.2
- NetApp SnapCenter: all versions
- Oracle Communications Offline Mediation Controller: 12.0.0.3.0
- Oracle Corporation Oracle ZFS Storage Appliance Kit: 8.8
- Red Hat Enterprise Linux: 8.0
- RedHat Software Collections: all versions
How to fix
Upgrade to a fixed version: lxml 4.6.2. Check the vendor advisory for mitigations.
References
- https://advisory.checkmarx.net/advisory/CX-2020-4286
- https://bugzilla.redhat.com/show_bug.cgi?id=1901633
- https://lists.debian.org/debian-lts-announce/2020/12/msg00028.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKG67GPGTV23KADT4D4GK4RMHSO4CIQL/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMHVKRUT22LVWNL3TB7HPSDHJT74Q3JK/
- https://security.netapp.com/advisory/ntap-20210521-0003/
- https://www.debian.org/security/2020/dsa-4810
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://advisory.checkmarx.net/advisory/CX-2020-4286
- https://bugzilla.redhat.com/show_bug.cgi?id=1901633
- https://lists.debian.org/debian-lts-announce/2020/12/msg00028.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKG67GPGTV23KADT4D4GK4RMHSO4CIQL/
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