Duplicate Advisory: Grav: Blueprint dynamic-data bare-function branch is denylist-gated and omits error_log, giving arbitrary file write
Grav before version 2.0.15 has an arbitrary file write vulnerability in its Blueprint dynamic-data bare-function validation. The vulnerability arises because the validation uses an incomplete denylist rather than a positive allowlist. Attackers with page-edit or blueprint-config permissions can exploit this flaw to invoke the error_log function via a data directive, allowing them to append PHP payloads to web-accessible files and potentially achieve remote code execution.
AI Analysis
Technical Summary
The vulnerability in Grav versions prior to 2.0.15 involves the Blueprint dynamic-data bare-function validation mechanism, which relies on an incomplete denylist instead of a positive allowlist. This flaw enables attackers who have page-edit or blueprint-config access to invoke the error_log function through a crafted data directive. By doing so, they can append arbitrary PHP code to files accessible via the web, leading to remote code execution.
Potential Impact
Successful exploitation allows an attacker with limited privileges (page-edit or blueprint-config access) to write arbitrary PHP code to web-accessible files, resulting in remote code execution. This compromises confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
A fix is available in Grav version 2.0.15. Users should upgrade to version 2.0.15 or later to remediate this vulnerability. No additional mitigation steps are indicated in the advisory.
Duplicate Advisory: Grav: Blueprint dynamic-data bare-function branch is denylist-gated and omits error_log, giving arbitrary file write
Description
Grav before version 2.0.15 has an arbitrary file write vulnerability in its Blueprint dynamic-data bare-function validation. The vulnerability arises because the validation uses an incomplete denylist rather than a positive allowlist. Attackers with page-edit or blueprint-config permissions can exploit this flaw to invoke the error_log function via a data directive, allowing them to append PHP payloads to web-accessible files and potentially achieve remote code execution.
CVSS v3.1
Score 8.8high
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Grav versions prior to 2.0.15 involves the Blueprint dynamic-data bare-function validation mechanism, which relies on an incomplete denylist instead of a positive allowlist. This flaw enables attackers who have page-edit or blueprint-config access to invoke the error_log function through a crafted data directive. By doing so, they can append arbitrary PHP code to files accessible via the web, leading to remote code execution.
Potential Impact
Successful exploitation allows an attacker with limited privileges (page-edit or blueprint-config access) to write arbitrary PHP code to web-accessible files, resulting in remote code execution. This compromises confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
A fix is available in Grav version 2.0.15. Users should upgrade to version 2.0.15 or later to remediate this vulnerability. No additional mitigation steps are indicated in the advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-fwwx-3362-3947
- Osv Schema Version
- 1.4.0
- Ecosystems
- ["Packagist"]
- Database Specific Severity
- CRITICAL
- Cvss Version
- 3.1
Threat ID: 6aac8de855bf5e2cf54900d3
Added to database: 09/18/2026, 01:03:36 UTC
Last enriched: 09/18/2026, 01:26:10 UTC
Last updated: 09/18/2026, 02:19:08 UTC
Views: 4
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.