Command execution via double-backslash denylist bypass
Published Jul 18, 2023 · Updated Oct 18, 2024
Server-side template injection in GetGrav Grav before 1.7.42.2 allows remote authenticated users to execute operating-system commands. Utils::isDangerousFunction returns false when a Twig callback name contains a backslash, so a double-backslash payload bypasses the dangerous-function denylist. Exploitation requires an Administrator account or Admin Panel access with page creation or update permission and executes commands as the web server process.
Summary
What happened
Server-side template injection in GetGrav Grav before 1.7.42.2 allows remote authenticated users to execute operating-system commands. Utils::isDangerousFunction returns false when a Twig callback name contains a backslash, so a double-backslash payload bypasses the dangerous-function denylist. Exploitation requires an Administrator account or Admin Panel access with page creation or update permission and executes commands as the web server process.
The record
- CVE
- CVE-2023-37897
- Published
- Jul 18, 2023
- Updated
- Oct 18, 2024
- Vendor
- GetGrav
- Product
- Grav
- Classifications
- CWE-393, CWE-74, T1059
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 18, 2023CVE publishedPublication date reported by the CVE source.
- Oct 18, 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=0 <1.7.42.2
- Affected versionversion=< 1.7.42.2
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
- Upstream double-backslash Twig payloadproof of concept · 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
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