A critical vulnerability has been identified in Laravel v11.x, a popular PHP web framework known for building modern, elegant web applications. This vulnerability, designated as CVE-2024-40075, is an XML External Entity (XXE) flaw that potentially allows attackers to execute arbitrary commands and access sensitive data.
Vulnerability Details
- Vulnerability ID: CVE-2024-40075
- Vulnerability Type: XML External Entity (XXE)
- Severity Level: High
- CVSS Score: Pending evaluation
- Affected Software: Laravel v11.x
Technical Analysis
The vulnerability exists in the handling of the __destruct function within the Monolog\Handler\Handler class, a core component of Laravel’s logging mechanism. Below is a detailed analysis of the exploit process:
- Tracing the __destruct Function:
- The __destruct function in the abstract class Monolog\Handler\Handler is called if not overridden by a subclass. This function ultimately calls the close method.
- Subclass Analysis:
- By identifying a subclass that overrides the close method but not the __destruct method, such as GroupHandler, the researcher traced the execution flow.
- Handler Iteration:
- In the GroupHandler’s close method, the code iterates through handlers and executes their close methods, leading to the discovery of the getStreamName method call.
- Trigger Identification:
- The getStreamName method invokes the md5 function, necessitating a search for a __tostring trigger. The researcher identified the Psy\Readline\Hoa\FileRead class as a critical component.
- Function Execution:
- The __tostring function calls the tostring function, which then calls the $this->stypes->format function, allowing exploitation to execute arbitrary commands.
Potential Impact
The CVE-2024-40075 vulnerability poses a serious risk as it allows malicious actors to manipulate XML input and perform unauthorized operations. This could lead to:
- Data breaches
- System compromises
- Unauthorized access to sensitive information
Given Laravel’s widespread use for web development, the impact of this vulnerability could be extensive, affecting numerous web applications globally.
Mitigation
Recommended Actions:
- Update Laravel: Users are strongly urged to update to the latest version of Laravel to protect their applications from this vulnerability.
- Input Validation: Implement robust input validation to sanitize and validate XML inputs.
- Disable External Entities: Disable XML external entity processing if not required by the application.
CVE-2024-40075 is a critical XXE vulnerability in Laravel v11.x that requires immediate attention. Users must update their Laravel installations and implement necessary security measures to mitigate potential risks. The widespread use of Laravel in web applications makes this vulnerability particularly concerning, necessitating swift action to prevent exploitation.
