CVE-2020-6816 Bleach vulnerable to mutation XSS via whitelisted math or svg and raw tag

What is CVE-2020-6816?

CVE-2020-6816 is a medium-severity cross-site scripting vulnerability in Fedoraproject Fedora, published on 24 Mar 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are whitelisted and the keyword argument strip=False.

Weakness: CWE-79

Which versions are affected by CVE-2020-6816?

3 open source packages ship an affected version, including bleach. It affects 2 products.

Products include Fedoraproject Fedora, Mozilla Bleach.

How do I fix CVE-2020-6816?

Upgrade bleach to 3.1.2 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2020-6816 being exploited?

There is no known exploitation of CVE-2020-6816 in the wild and no public exploit code.

Other vulnerabilities in Fedoraproject Fedora

• CVE-2024-4577 PHP-CGI OS Command Injection Exploited Critical 9.8
• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-6816, DSA-4643-1, GHSA-m6xf-fq7q-8743, PYSEC-2020-28, UBUNTU-CVE-2020-6816.