CVE-2007-2636 in phpTodo
Summary
by MITRE
Unspecified vulnerability in phpTodo before 0.8.1 allows remote attackers to have an unknown impact via newlines in regular expressions to (1) index.php, (2) feed.php, (3) prefs.php, and (4) todolist.php; and (5) classTodoItem.php and (6) phpTodoUser.php in libs/. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/31/2018
This vulnerability resides in phpTodo version 0.8.0 and earlier, representing a classic input validation flaw that could potentially enable remote code execution or information disclosure depending on how the application processes user-supplied data. The issue stems from insufficient sanitization of user inputs when regular expressions are processed within the application's core files. The vulnerability specifically affects multiple key components including the main index.php, feed.php, prefs.php, and todolist.php scripts, as well as the supporting library files classTodoItem.php and phpTodoUser.php located in the libs/ directory. This cross-cutting impact across multiple application modules indicates a fundamental flaw in the input handling mechanism rather than isolated code issues.
The technical exploitation of this vulnerability occurs when remote attackers inject newline characters into regular expression patterns that are processed by the application. These newline characters can potentially disrupt the regular expression engine's parsing behavior, leading to unexpected execution paths within the application's code. When these malformed patterns are processed through the vulnerable phpTodo components, the system may interpret the injected characters in ways that bypass normal security controls. The vulnerability's classification as unspecified impact suggests that the consequences could range from denial of service conditions to more severe outcomes including arbitrary code execution, depending on the specific context and how the regular expression engine handles the malformed input.
The operational impact of this vulnerability extends beyond simple data corruption or service disruption. Attackers could potentially leverage this weakness to execute malicious code on the target system, access sensitive user data, or gain unauthorized administrative privileges. The vulnerability affects the core functionality of phpTodo, which is a web-based task management application, making it particularly dangerous for organizations that rely on this tool for business operations. The fact that multiple files are affected indicates that the vulnerability exists at a fundamental level within the application's architecture rather than being isolated to specific functions, increasing the attack surface and potential impact of exploitation.
Security professionals should approach this vulnerability through multiple defensive layers to ensure comprehensive protection. The primary mitigation strategy involves upgrading to phpTodo version 0.8.1 or later, which contains the necessary patches to address the input validation issues. Additionally, implementing proper input sanitization measures within the application code, particularly around regular expression processing, can provide defense-in-depth protection. Organizations should also consider implementing web application firewalls that can detect and block malicious input patterns targeting this specific vulnerability. The vulnerability aligns with CWE-185, which covers improper regular expression handling, and could potentially map to ATT&CK techniques involving command and control communications or privilege escalation through application vulnerabilities. Regular monitoring of application logs for unusual patterns in user input, particularly around newline characters in regular expression contexts, should be implemented as part of ongoing security operations.