Ecosyste.ms: Advisories
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Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWhyM2gteDZncS1ycWNw
Cross site scripting via HTML attributes in the back end
Impact
It is possible for untrusted users to inject malicious code into HTML attributes in the back end, which will be executed both in the element preview (back end) and on the website (front end).
Installations are only affected if there are untrusted back end users who have the rights to modify HTML fields (e.g. TinyMCE).
Patches
Update to Contao 4.4.56, 4.9.18 or 4.11.7
Workarounds
Disable all fields that allow HTML for untrusted back end users or disable the login for these users.
References
https://contao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end
For more information
If you have any questions or comments about this advisory, open an issue in contao/contao.
Credits
Thanks to Mikhail Khramenkov and Moritz Vondano for reporting this security issue.
Permalink: https://github.com/advisories/GHSA-hr3h-x6gq-rqcpJSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWhyM2gteDZncS1ycWNw
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Moderate
Classification: General
Published: over 3 years ago
Updated: 11 months ago
CVSS Score: 5.9
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
EPSS Percentage: 0.0005
EPSS Percentile: 0.21439
Identifiers: GHSA-hr3h-x6gq-rqcp, CVE-2021-35955
References:
- https://github.com/contao/contao/security/advisories/GHSA-hr3h-x6gq-rqcp
- https://nvd.nist.gov/vuln/detail/CVE-2021-35955
- https://contao.org/en/news/contao-4-9-16-and-4-11-5-are-available.html
- https://contao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end.html
- https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-35955.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-35955.yaml
- https://github.com/advisories/GHSA-hr3h-x6gq-rqcp
Blast Radius: 19.4
Affected Packages
packagist:contao/core-bundle
Dependent packages: 1,961Dependent repositories: 1,932
Downloads: 1,270,424 total
Affected Version Ranges: >= 4.10.0, < 4.11.7, >= 4.5.0, < 4.9.18, >= 4.0.0, < 4.4.56
Fixed in: 4.11.7, 4.9.18, 4.4.56
All affected versions: 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.2.0, 4.2.1, 4.2.2, 4.2.3, 4.2.4, 4.2.5, 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.3.4, 4.3.5, 4.3.6, 4.3.7, 4.3.8, 4.3.9, 4.3.10, 4.3.11, 4.4.0, 4.4.1, 4.4.2, 4.4.3, 4.4.4, 4.4.5, 4.4.6, 4.4.7, 4.4.8, 4.4.9, 4.4.10, 4.4.11, 4.4.12, 4.4.13, 4.4.14, 4.4.15, 4.4.16, 4.4.17, 4.4.18, 4.4.19, 4.4.20, 4.4.21, 4.4.22, 4.4.23, 4.4.24, 4.4.25, 4.4.26, 4.4.27, 4.4.28, 4.4.29, 4.4.30, 4.4.31, 4.4.32, 4.4.33, 4.4.34, 4.4.35, 4.4.36, 4.4.37, 4.4.38, 4.4.39, 4.4.40, 4.4.41, 4.4.42, 4.4.43, 4.4.44, 4.4.45, 4.4.46, 4.4.47, 4.4.48, 4.4.49, 4.4.50, 4.4.51, 4.4.52, 4.4.53, 4.4.54, 4.4.55, 4.5.0, 4.5.1, 4.5.2, 4.5.3, 4.5.4, 4.5.5, 4.5.6, 4.5.7, 4.5.8, 4.5.9, 4.5.10, 4.5.11, 4.5.12, 4.5.13, 4.5.14, 4.6.0, 4.6.1, 4.6.2, 4.6.3, 4.6.4, 4.6.5, 4.6.6, 4.6.7, 4.6.8, 4.6.9, 4.6.10, 4.6.11, 4.6.12, 4.6.13, 4.6.14, 4.7.0, 4.7.1, 4.7.2, 4.7.3, 4.7.4, 4.7.5, 4.7.6, 4.7.7, 4.8.0, 4.8.1, 4.8.2, 4.8.3, 4.8.4, 4.8.5, 4.8.6, 4.8.7, 4.8.8, 4.9.0, 4.9.1, 4.9.2, 4.9.3, 4.9.4, 4.9.5, 4.9.6, 4.9.7, 4.9.8, 4.9.9, 4.9.10, 4.9.11, 4.9.12, 4.9.13, 4.9.14, 4.9.15, 4.9.16, 4.9.17, 4.10.0, 4.10.1, 4.10.2, 4.10.3, 4.10.4, 4.10.5, 4.10.6, 4.10.7, 4.11.0, 4.11.1, 4.11.2, 4.11.3, 4.11.4, 4.11.5, 4.11.6
All unaffected versions: 4.4.56, 4.4.57, 4.9.18, 4.9.19, 4.9.20, 4.9.21, 4.9.22, 4.9.23, 4.9.24, 4.9.25, 4.9.26, 4.9.27, 4.9.28, 4.9.29, 4.9.30, 4.9.31, 4.9.32, 4.9.33, 4.9.34, 4.9.35, 4.9.36, 4.9.37, 4.9.38, 4.9.39, 4.9.40, 4.9.41, 4.9.42, 4.11.7, 4.11.8, 4.11.9, 4.12.0, 4.12.1, 4.12.2, 4.12.3, 4.12.4, 4.12.5, 4.12.6, 4.12.7, 4.13.0, 4.13.1, 4.13.2, 4.13.3, 4.13.4, 4.13.5, 4.13.6, 4.13.7, 4.13.8, 4.13.9, 4.13.10, 4.13.11, 4.13.12, 4.13.13, 4.13.14, 4.13.15, 4.13.16, 4.13.17, 4.13.18, 4.13.19, 4.13.20, 4.13.21, 4.13.22, 4.13.23, 4.13.24, 4.13.25, 4.13.26, 4.13.27, 4.13.28, 4.13.29, 4.13.30, 4.13.31, 4.13.32, 4.13.33, 4.13.34, 4.13.35, 4.13.36, 4.13.37, 4.13.38, 4.13.39, 4.13.40, 4.13.41, 4.13.42, 4.13.43, 4.13.44, 4.13.45, 4.13.46, 4.13.47, 4.13.48, 4.13.49, 4.13.50, 5.0.0, 5.0.1, 5.0.2, 5.0.3, 5.0.4, 5.0.5, 5.0.6, 5.0.7, 5.0.8, 5.0.9, 5.0.10, 5.1.0, 5.1.1, 5.1.2, 5.1.3, 5.1.4, 5.1.5, 5.1.6, 5.1.7, 5.1.8, 5.1.9, 5.1.10, 5.1.11, 5.2.0, 5.2.1, 5.2.2, 5.2.3, 5.2.4, 5.2.5, 5.2.6, 5.2.7, 5.2.8, 5.2.9, 5.2.10, 5.3.0, 5.3.1, 5.3.2, 5.3.3, 5.3.4, 5.3.5, 5.3.6, 5.3.7, 5.3.8, 5.3.9, 5.3.10, 5.3.11, 5.3.12, 5.3.13, 5.3.14, 5.3.15, 5.3.16, 5.3.17, 5.3.18, 5.3.19, 5.4.0, 5.4.1, 5.4.2, 5.4.3, 5.4.4, 5.4.5, 5.4.6, 5.4.7
packagist:contao/contao
Dependent packages: 8Dependent repositories: 7
Downloads: 13,519 total
Affected Version Ranges: >= 4.10.0, < 4.11.7, >= 4.5.0, < 4.9.18, >= 4.0.0, < 4.4.56
Fixed in: 4.11.7, 4.9.18, 4.4.56
All affected versions: 4.4.22, 4.4.23, 4.4.24, 4.4.25, 4.4.26, 4.4.27, 4.4.28, 4.4.29, 4.4.30, 4.4.31, 4.4.32, 4.4.33, 4.4.34, 4.4.35, 4.4.36, 4.4.37, 4.4.38, 4.4.39, 4.4.40, 4.4.41, 4.4.42, 4.4.43, 4.4.44, 4.4.45, 4.4.46, 4.4.47, 4.4.48, 4.4.49, 4.4.50, 4.4.51, 4.4.52, 4.4.53, 4.4.54, 4.4.55, 4.5.13, 4.5.14, 4.6.0, 4.6.1, 4.6.2, 4.6.3, 4.6.4, 4.6.5, 4.6.6, 4.6.7, 4.6.8, 4.6.9, 4.6.10, 4.6.11, 4.6.12, 4.6.13, 4.6.14, 4.7.0, 4.7.1, 4.7.2, 4.7.3, 4.7.4, 4.7.5, 4.7.6, 4.7.7, 4.8.0, 4.8.1, 4.8.2, 4.8.3, 4.8.4, 4.8.5, 4.8.6, 4.8.7, 4.8.8, 4.9.0, 4.9.1, 4.9.2, 4.9.3, 4.9.4, 4.9.5, 4.9.6, 4.9.7, 4.9.8, 4.9.9, 4.9.10, 4.9.11, 4.9.12, 4.9.13, 4.9.14, 4.9.15, 4.9.16, 4.9.17, 4.10.0, 4.10.1, 4.10.2, 4.10.3, 4.10.4, 4.10.5, 4.10.6, 4.10.7, 4.11.0, 4.11.1, 4.11.2, 4.11.3, 4.11.4, 4.11.5, 4.11.6
All unaffected versions: 4.4.56, 4.4.57, 4.9.18, 4.9.19, 4.9.20, 4.9.21, 4.9.22, 4.9.23, 4.9.24, 4.9.25, 4.9.26, 4.9.27, 4.9.28, 4.9.29, 4.9.30, 4.9.31, 4.9.32, 4.9.33, 4.9.34, 4.9.35, 4.9.36, 4.9.37, 4.9.38, 4.9.39, 4.9.40, 4.9.41, 4.9.42, 4.11.7, 4.11.8, 4.11.9, 4.12.0, 4.12.1, 4.12.2, 4.12.3, 4.12.4, 4.12.5, 4.12.6, 4.12.7, 4.13.0, 4.13.1, 4.13.2, 4.13.3, 4.13.4, 4.13.5, 4.13.6, 4.13.7, 4.13.8, 4.13.9, 4.13.10, 4.13.11, 4.13.12, 4.13.13, 4.13.14, 4.13.15, 4.13.16, 4.13.17, 4.13.18, 4.13.19, 4.13.20, 4.13.21, 4.13.22, 4.13.23, 4.13.24, 4.13.25, 4.13.26, 4.13.27, 4.13.28, 4.13.29, 4.13.30, 4.13.31, 4.13.32, 4.13.33, 4.13.34, 4.13.35, 4.13.36, 4.13.37, 4.13.38, 4.13.39, 4.13.40, 4.13.41, 4.13.42, 4.13.43, 4.13.44, 4.13.45, 4.13.46, 4.13.47, 4.13.48, 4.13.49, 4.13.50, 5.0.0, 5.0.1, 5.0.2, 5.0.3, 5.0.4, 5.0.5, 5.0.6, 5.0.7, 5.0.8, 5.0.9, 5.0.10, 5.1.0, 5.1.1, 5.1.2, 5.1.3, 5.1.4, 5.1.5, 5.1.6, 5.1.7, 5.1.8, 5.1.9, 5.1.10, 5.1.11, 5.2.0, 5.2.1, 5.2.2, 5.2.3, 5.2.4, 5.2.5, 5.2.6, 5.2.7, 5.2.8, 5.2.9, 5.2.10, 5.3.0, 5.3.1, 5.3.2, 5.3.3, 5.3.4, 5.3.5, 5.3.6, 5.3.7, 5.3.8, 5.3.9, 5.3.10, 5.3.11, 5.3.12, 5.3.13, 5.3.14, 5.3.15, 5.3.16, 5.3.17, 5.3.18, 5.3.19, 5.3.20, 5.4.0, 5.4.1, 5.4.2, 5.4.3, 5.4.4, 5.4.5, 5.4.6, 5.4.7, 5.4.8