Content Security Policy bypass via uninherited XSLT policy
Published Jan 8, 2020 · Updated Aug 5, 2024
Content Security Policy bypass in Mozilla Firefox before 72 allows remote attackers to execute blocked script through crafted XML. The XSLT transformation creates a result document without inheriting the XML document's CSP, so stylesheet script and event handlers execute. A victim must open attacker-controlled XML that applies the crafted XSL stylesheet; resulting script runs with the transformed page's web-content privileges.
Summary
What happened
Content Security Policy bypass in Mozilla Firefox before 72 allows remote attackers to execute blocked script through crafted XML. The XSLT transformation creates a result document without inheriting the XML document's CSP, so stylesheet script and event handlers execute. A victim must open attacker-controlled XML that applies the crafted XSL stylesheet; resulting script runs with the transformed page's web-content privileges.
The record
- CVE
- CVE-2019-17020
- Published
- Jan 8, 2020
- Updated
- Aug 5, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-611, 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
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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?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- XML and XSL Content Security Policy bypass test caseproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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