CVE-2023-43661 in Cachet
Summary
by MITRE • 10/25/2023
Cachet, the open-source status page system. Prior to the 2.4 branch, a template functionality which allows users to create templates allows them to execute any code on the server during the bad filtration and old twig version. Commit 6fb043e109d2a262ce3974e863c54e9e5f5e0587 of the 2.4 branch contains a patch for this issue.
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Analysis
by VulDB Data Team • 10/31/2023
CVE-2023-43661 represents a critical server-side template injection vulnerability affecting Cachet versions prior to the 2.4 branch. This vulnerability exists within the template creation functionality that enables users to define custom templates for status page displays. The flaw stems from inadequate input validation and sanitization processes that fail to properly filter user-supplied template content before processing. Attackers can exploit this weakness by crafting malicious template code that gets executed on the server during template rendering operations. The vulnerability is particularly dangerous because it leverages the outdated Twig templating engine version, which contains known security flaws that allow arbitrary code execution when processing untrusted template input.
The technical exploitation of this vulnerability occurs through the template system's failure to properly sanitize user inputs during template creation and rendering phases. When users create templates, the system accepts raw template code without adequate security checks, allowing malicious payloads to be embedded within template files. This creates a server-side code execution vector where attackers can inject malicious code that executes with the privileges of the web server process. The vulnerability is classified under CWE-94, which specifically addresses "Improper Control of Generation of Code ('Code Injection')" and aligns with ATT&CK technique T1190 for "Exploit Public-Facing Application" and T1059.001 for "Command and Scripting Interpreter: PowerShell" or similar execution methods. The patched commit 6fb043e109d2a262ce3974e863c54e9e5f5e0587 addresses this by implementing proper input validation and sanitization mechanisms for template content.
The operational impact of CVE-2023-43661 extends beyond simple code execution to potentially compromise entire server infrastructures. Successful exploitation allows attackers to gain unauthorized access to the server hosting the Cachet status page, enabling them to read sensitive data, modify system configurations, install backdoors, or launch further attacks against internal networks. The vulnerability affects organizations that rely on Cachet for monitoring and displaying system status information, potentially exposing critical infrastructure monitoring systems to compromise. Organizations using older versions of Cachet are particularly at risk as they lack the patched security measures that prevent malicious template code from executing. This vulnerability demonstrates the importance of keeping templating engines and application frameworks up to date, as the outdated Twig version used in affected releases contained known security issues that made exploitation possible.
Organizations should immediately upgrade to Cachet 2.4 or later versions to mitigate this vulnerability, as the patch addresses the core issue through enhanced input validation and proper template sanitization. System administrators should also implement additional security measures including regular template audits, monitoring for suspicious template modifications, and restricting user privileges for template creation functionality. The vulnerability highlights the necessity of following security best practices such as input validation, least privilege principles, and regular security updates. Organizations should conduct comprehensive security assessments of their Cachet installations to identify any potential exploitation attempts and ensure that all template creation processes are properly secured against malicious input injection. Additionally, implementing web application firewalls and monitoring for unusual template processing activities can provide additional layers of protection against similar vulnerabilities in the future.