CVE-2007-4385 in Stinger
Summary
by MITRE
OWASP Stinger before 2.5 allows remote attackers to bypass input validation routines by using multipart encoded requests instead of form-urlencoded requests. NOTE: this might be used to expose vulnerabilities in applications that would otherwise be protected by the validation routines.
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Analysis
by VulDB Data Team • 02/16/2025
The vulnerability described in CVE-2007-4385 affects the OWASP Stinger web application firewall tool version 2.4 and earlier, representing a critical input validation bypass flaw that undermines the security protections intended by the application. This vulnerability specifically targets the validation routines implemented within Stinger, which are designed to filter and sanitize incoming HTTP requests to prevent malicious input from reaching backend applications. The flaw exploits a fundamental weakness in how the tool processes different types of HTTP request encodings, creating a pathway for attackers to circumvent the security controls that would normally block potentially harmful input.
The technical mechanism behind this vulnerability stems from Stinger's differential handling of multipart and form-urlencoded HTTP request formats. When requests are submitted using the standard application/x-www-form-urlencoded encoding, Stinger's validation routines properly inspect and filter the input parameters. However, when attackers utilize multipart/form-data encoding, which is commonly used for file uploads and complex data submissions, the validation logic fails to properly process these requests, allowing malicious content to pass through undetected. This encoding difference creates a gap in the validation layer where the tool's security controls are bypassed, essentially creating a backdoor for attackers to submit crafted input that would normally be rejected.
The operational impact of this vulnerability extends beyond simple bypass of input validation, as it can potentially expose underlying applications to various attack vectors that would otherwise be protected. When Stinger's validation routines are circumvented through multipart encoding, it creates opportunities for attackers to exploit other vulnerabilities within the target applications, including but not limited to cross-site scripting, SQL injection, and command injection attacks. The vulnerability essentially undermines the core security premise of Stinger as a protective layer, allowing threat actors to escalate their attacks and potentially gain unauthorized access to sensitive data or system resources. This makes the vulnerability particularly dangerous in environments where Stinger is deployed as a primary security control.
Security practitioners should consider this vulnerability in the context of CWE-20, which describes improper input validation, and its relationship to ATT&CK technique T1190, which involves exploiting vulnerabilities in web applications. The flaw demonstrates how encoding variations can create unexpected security gaps in defensive mechanisms, highlighting the importance of comprehensive testing across different HTTP request formats. Organizations should prioritize immediate remediation by upgrading to OWASP Stinger version 2.5 or later, which contains the necessary fixes to properly handle multipart encoded requests. Additionally, security teams should implement additional monitoring and detection capabilities to identify unusual request patterns that might indicate exploitation attempts, while maintaining proper input validation at multiple layers of the application stack to ensure defense in depth principles are maintained.