CVE-2021-35955

描述

### 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](https://github.com/contao/contao/issues/new/choose). ### Credits Thanks to Mikhail Khramenkov and Moritz Vondano for reporting this security issue.

如何修補 CVE-2021-35955

要修補 CVE-2021-35955,請將受影響套件升級到下列已修補版本。

• —升級至 4.4.56 或更新版本
• —升級至 4.4.56 或更新版本

CVE-2021-35955 正在被利用嗎?

低 — EPSS 為 0.6%,目前沒有觀察到大規模利用活動。

受影響套件(2)

• >= 4.0.0, < 4.4.56
• >= 4.0.0, < 4.4.56

CVSS 分數

參考連結(7)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-35955
• PATCHgithub.com/contao/contao
• WEBcontao.org/en/news/contao-4-9-16-and-4-11-5-are-available.html
• WEBcontao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end.html