GHSA-m6xf-fq7q-8743
Suggest an improvement- Source
- https://github.com/advisories/GHSA-m6xf-fq7q-8743
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/03/GHSA-m6xf-fq7q-8743/GHSA-m6xf-fq7q-8743.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-m6xf-fq7q-8743
- Aliases
- Published
- 2020-03-24T15:06:32Z
- Modified
- 2024-09-12T20:50:49.651546Z
- Severity
-
- 6.1 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
- 5.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N CVSS Calculator
- Summary
- Bleach vulnerable to mutation XSS via whitelisted math or svg and raw tag
- Details
-
Impact
A mutation XSS affects users calling
bleach.cleanwith all of:- the
svgormathin the allowed/whitelisted tags - an RCDATA tag (see below) in the allowed/whitelisted tags
- the keyword argument
strip=False
Patches
Users are encouraged to upgrade to bleach v3.1.2 or greater.
Workarounds
modify
bleach.cleancalls to usestrip=True, or not whitelistmathorsvgtags and one or more of the following tags:script noscript style noframes xmp noembed iframeA strong Content-Security-Policy without
unsafe-inlineandunsafe-evalscript-srcs) will also help mitigate the risk.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1621692
- https://cure53.de/fp170.pdf
- https://nvd.nist.gov/vuln/detail/CVE-2020-6816
- https://www.checkmarx.com/blog/vulnerabilities-discovered-in-mozilla-bleach
Credits
- Reported by Yaniv Nizry from the CxSCA AppSec group at Checkmarx
For more information
If you have any questions or comments about this advisory:
- Open an issue at https://github.com/mozilla/bleach/issues
- Email us at security@mozilla.org
- the
- References
-
- https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743
- https://nvd.nist.gov/vuln/detail/CVE-2020-6816
- https://advisory.checkmarx.net/advisory/CX-2020-4277
- https://github.com/mozilla/bleach
- https://github.com/mozilla/bleach/releases/tag/v3.1.2
- https://github.com/pypa/advisory-database/tree/main/vulns/bleach/PYSEC-2020-28.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EDQU2SZLZMSSACCBUBJ6NOSRNNBDYFW5
- https://www.checkmarx.com/blog/vulnerabilities-discovered-in-mozilla-bleach
Affected packages
PyPI / bleach
Package
- Name
- bleach
- View open source insights on deps.dev
- Purl
- pkg:pypi/bleach