CVE-2016-5007 in Retail Xstore Point of Service
Summary
by MITRE
Both Spring Security 3.2.x, 4.0.x, 4.1.0 and the Spring Framework 3.2.x, 4.0.x, 4.1.x, 4.2.x rely on URL pattern mappings for authorization and for mapping requests to controllers respectively. Differences in the strictness of the pattern matching mechanisms, for example with regards to space trimming in path segments, can lead Spring Security to not recognize certain paths as not protected that are in fact mapped to Spring MVC controllers that should be protected. The problem is compounded by the fact that the Spring Framework provides richer features with regards to pattern matching as well as by the fact that pattern matching in each Spring Security and the Spring Framework can easily be customized creating additional differences.
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Analysis
by VulDB Data Team • 03/03/2023
The vulnerability identified as CVE-2016-5007 represents a critical authorization bypass flaw affecting multiple versions of the Spring Framework and Spring Security ecosystems. This issue stems from fundamental discrepancies in how URL pattern matching is implemented between the Spring Security module and the Spring Framework itself, creating potential security gaps that could allow unauthorized access to protected resources. The vulnerability specifically manifests when Spring Security's authorization mechanisms fail to properly recognize certain paths as requiring protection, despite those same paths being mapped to Spring MVC controllers that should be secured. This inconsistency arises from differing approaches to pattern matching strictness, particularly concerning space trimming in path segments, which creates opportunities for attackers to exploit the gap between what Spring Security considers protected and what the Spring Framework actually maps to controllers.
The technical flaw in CVE-2016-5007 operates through a pattern matching divergence that exists between Spring Security's authorization checks and Spring Framework's controller mapping capabilities. When path segments contain trailing spaces or other whitespace characters, the two systems handle these differently, causing Spring Security to potentially overlook certain paths that are actually mapped to protected controllers through the Spring Framework's more permissive pattern matching. This discrepancy can be particularly dangerous because Spring Framework's pattern matching capabilities are more sophisticated and feature-rich compared to Spring Security's implementation, creating multiple potential points of failure where authorization decisions may be made incorrectly. The vulnerability is further exacerbated by the fact that both frameworks support extensive customization of their pattern matching behaviors, which can introduce additional variations and inconsistencies that attackers might exploit to bypass security controls.
The operational impact of CVE-2016-5007 extends beyond simple unauthorized access, potentially allowing attackers to execute arbitrary code or gain elevated privileges within applications that rely on Spring Security for access control. Applications affected by this vulnerability may be exposed to scenarios where sensitive endpoints are accessible to unauthorized users, particularly when those endpoints are mapped through Spring MVC controllers that should be protected by Spring Security's authorization mechanisms. The complexity of this issue means that the vulnerability can manifest in various forms depending on how applications are configured, making it particularly challenging to detect and remediate. Organizations using affected versions of Spring Framework and Spring Security may experience situations where legitimate security controls are bypassed, leading to potential data breaches or system compromise, especially in environments where applications have complex URL routing configurations.
Mitigation strategies for CVE-2016-5007 require careful attention to both framework versions and configuration practices. The primary recommendation involves upgrading to patched versions of Spring Framework and Spring Security where the pattern matching inconsistencies have been resolved. Organizations should also implement consistent URL normalization practices across their applications, ensuring that path segments are handled uniformly regardless of which framework component performs the authorization check. Configuration review becomes critical as administrators must examine how pattern matching is customized in both frameworks, particularly focusing on whitespace handling and path segment processing. Security teams should conduct comprehensive testing of URL access controls, paying special attention to edge cases involving spaces and special characters in path segments. The vulnerability aligns with CWE-284, which addresses improper access control, and can be categorized under ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting, as attackers may exploit this weakness to gain unauthorized access to protected application resources.