Cross-site scripting via unescaped pasted CSS
Published Jan 8, 2020 · Updated Aug 5, 2024
Cross-site scripting in Mozilla Firefox before 72 and Firefox ESR before 68.4 allows remote attackers to execute script through pasted CSS. The clipboard CSS sanitizer leaves angle brackets in a pasted style tag, and DOM serialization preserves them as executable markup when a page copies that node's innerHTML into another innerHTML sink. Exploitation requires user interaction with a rich-text editor and a page that performs the second innerHTML assignment; the result is script execution in that page's context.
Summary
What happened
Cross-site scripting in Mozilla Firefox before 72 and Firefox ESR before 68.4 allows remote attackers to execute script through pasted CSS. The clipboard CSS sanitizer leaves angle brackets in a pasted style tag, and DOM serialization preserves them as executable markup when a page copies that node's innerHTML into another innerHTML sink. Exploitation requires user interaction with a rich-text editor and a page that performs the second innerHTML assignment; the result is script execution in that page's context.
The record
- CVE
- CVE-2019-17022
- Published
- Jan 8, 2020
- Updated
- Aug 5, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 8, 2020CVE publishedPublication date reported by the CVE source.
- Aug 5, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=before 72
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Mozilla Bugzilla WYSIWYG mutation-XSS reproductionfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo