Kurz gesagt
- CVE-2020-26293 ist eine Schwachstelle (MITTEL (CVSS 6.1)) in HtmlSanitizer, htmlsanitizer (htmlsanitizer project).
- Wahrscheinlichkeit einer Ausnutzung in den nächsten 30 Tagen (EPSS): 1.0%, höher als bei 63.3% aller Schwachstellen.
- Abhilfe: auf 5.0.372 oder neuer aktualisieren.
Description
Impact
If you have explicitly allowed the <style> tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the <style> tag so there is no risk if you have not explicitly allowed the <style> tag.
Patches
The problem has been fixed in version 5.0.372.
Workarounds
Remove the <style> tag from the set of allowed tags.
For more information
If you have any questions or comments about this advisory open an issue in https://github.com/mganss/HtmlSanitizer
Credits
This issue was discovered by Michal Bentkowski of Securitum.
NVD description
HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer before version 5.0.372, there is a possible XSS bypass if style tag is allowed. If you have explicitly allowed the `<style>` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `<style>` tag so there is no risk if you have not explicitly allowed the `<style>` tag. The problem has been fixed in version 5.0.372.
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