CVE-2016-6026 in Sterling Secure Proxy
Summary
by MITRE
The Configuration Manager in IBM Sterling Secure Proxy (SSP) 3.4.2 before 3.4.2.0 iFix 8 and 3.4.3 before 3.4.3.0 iFix 1 allows man-in-the-middle attackers to obtain sensitive information via an HTTP method that is neither GET nor POST.
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Analysis
by VulDB Data Team • 05/04/2019
The vulnerability identified as CVE-2016-6026 affects IBM Sterling Secure Proxy version 3.4.2 prior to iFix 8 and 3.4.3 prior to iFix 1, representing a significant security flaw in the configuration management component of this enterprise security solution. This issue falls under the category of information disclosure vulnerabilities and specifically targets the handling of HTTP requests within the proxy server implementation. The vulnerability manifests when the system processes HTTP methods that are neither GET nor POST, creating an exploitable condition that can be leveraged by malicious actors positioned in the network path between communicating parties.
The technical root cause of this vulnerability stems from improper validation and handling of HTTP methods within the IBM Sterling Secure Proxy configuration manager. When the system encounters HTTP requests using methods such as PUT, DELETE, HEAD, OPTIONS, or custom HTTP verbs, it fails to properly sanitize or validate the request parameters before processing them. This inadequate input validation creates a pathway for attackers to manipulate the request flow and potentially extract sensitive information that should remain protected within the secure proxy environment. The vulnerability specifically exploits the difference in how the system handles various HTTP methods, where GET and POST requests are properly secured while other methods are not subjected to the same level of scrutiny.
From an operational impact perspective, this vulnerability poses a serious threat to organizations relying on IBM Sterling Secure Proxy for their security infrastructure. Attackers can exploit this weakness to perform man-in-the-middle attacks, potentially gaining access to sensitive configuration data, authentication credentials, or other confidential information transmitted through the proxy. The vulnerability's exploitation does not require authentication or privileged access, making it particularly dangerous as it can be leveraged by remote attackers. Organizations using this version of the proxy may experience unauthorized data access, potential compromise of the entire security infrastructure, and violation of data protection policies that rely on the proxy's secure handling of communications.
The security implications of this vulnerability align with CWE-200, which addresses "Information Exposure," and represents a clear violation of secure coding practices in HTTP request handling. According to ATT&CK framework, this vulnerability maps to T1046 Network Service Scanning and T1566 Phishing, as attackers can use this weakness to gather information about the network infrastructure and potentially escalate their attacks. The vulnerability also relates to T1567 Credential Access through the potential exposure of authentication-related information during HTTP method processing. Organizations should consider implementing network segmentation, monitoring for unusual HTTP method usage patterns, and deploying additional network security controls to mitigate potential exploitation. The recommended remediation involves applying the appropriate iFix patches provided by IBM, which address the improper HTTP method handling and ensure proper validation of all incoming requests regardless of their HTTP method type, thereby closing this information disclosure pathway.
The broader implications extend beyond immediate exploitation potential, as this vulnerability demonstrates the importance of comprehensive HTTP request handling validation in enterprise security products. The issue highlights the need for robust input validation across all HTTP methods and underscores the critical requirement for security products to maintain consistent protection levels regardless of the request type being processed. Organizations should conduct thorough vulnerability assessments of their security infrastructure to identify similar issues in other components and establish more rigorous testing procedures for HTTP method handling in all network security solutions.