Grav - Stored CSS Injection via Markdown Image resize() Action
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2.0.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
Grav before 2.0.0 (affected through 2.0.0-rc.9 and the 2.0 branch) contains a stored CSS injection vulnerability in the Markdown image resize() media action. Prior media hardening rejects direct ?style= payloads and unsafe attribute() fallbacks, but the resize() action in Excerpts::processMediaActions() writes caller-controlled values directly into the image's styleAttributes. A lower-privileged content editor who can edit page Markdown can store a crafted image URL with semicolon-delimited CSS declarations in the resize parameters, which are rendered into the final <img style=...> attribute when a higher-privileged reviewer/admin views the page or preview. This does not require JavaScript execution but enables UI redress/overlay and content-manipulation attacks (e.g., a full-viewport fixed overlay). Fixed in 2.0.0.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Grav Grav
From 2.0.0-rc.9 · fixed in 2.0.0
- getgrav/gravPackagist
From 2.0.0-rc.9 · fixed in 2.0.0