CVE-2024-28119 in grav
Summary
by MITRE • 03/22/2024
Grav is an open-source, flat-file content management system. Prior to version 1.7.45, due to the unrestricted access to twig extension class from grav context, an attacker can redefine the escape function and execute arbitrary commands. Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance. Version 1.7.45 contains a patch for this issue.
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Analysis
by VulDB Data Team • 01/03/2025
The vulnerability CVE-2024-28119 affects Grav, a popular open-source flat-file content management system that relies heavily on Twig templating engine for dynamic content rendering. This security flaw represents a critical privilege escalation vulnerability that allows attackers to execute arbitrary code on affected systems. The issue stems from the unrestricted access to Twig extension classes within the Grav application context, creating a dangerous attack surface that can be exploited by malicious actors. The vulnerability specifically targets the escape function within Twig processing, which can be redefined by unauthorized users to gain full system control.
The technical implementation of this vulnerability involves the manipulation of Twig's template processing capabilities through front matter configuration in static pages. Any administrative user with permissions to create or edit pages can enable Twig processing by adding specific directives to the front matter of content files. This unsandboxed execution environment allows the attacker to redefine core Twig functions including the escape function, which serves as the primary vector for arbitrary code execution. The flaw exists because Grav does not properly validate or restrict access to Twig extension classes, enabling attackers to leverage legitimate administrative privileges for malicious purposes.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and privilege escalation. An attacker who gains access to an administrative account can exploit this vulnerability to execute arbitrary commands on the server hosting the Grav instance. This capability allows for data exfiltration, system modification, and potential lateral movement within network environments. The vulnerability affects all Grav installations prior to version 1.7.45, making it a widespread concern for organizations relying on this content management system. The attack requires only administrative access to the Grav instance, which is often more accessible than direct system-level privileges.
Organizations should immediately upgrade to Grav version 1.7.45 or later to mitigate this vulnerability, as this release contains the necessary patches to address the unrestricted access to Twig extension classes. System administrators should also implement additional security measures including regular access reviews, monitoring of administrative activities, and network segmentation to limit potential damage from compromised accounts. The vulnerability aligns with CWE-264, which addresses permissions, privileges, and access controls, and corresponds to ATT&CK technique T1059.007 for command and scripting interpreter. Additionally, this vulnerability demonstrates characteristics of privilege escalation through code injection, making it particularly dangerous in multi-user environments where administrative access is not properly restricted.