CVE-2013-2950 in WebSphere Portal
Summary
by MITRE
CRLF injection vulnerability in IBM WebSphere Portal 6.1.0.x before 6.1.0.3 CF26, 6.1.5.x before 6.1.5 CF26, 7.0.0.x before 7.0.0.2 CF21, and 8.0.0.x through 8.0.0.1 CF5, when home substitution (aka uri.home.substitution) is enabled, allows remote authenticated users to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 05/14/2021
The vulnerability described in CVE-2013-2950 represents a critical CRLF injection flaw within IBM WebSphere Portal software versions prior to specific cumulative fixes. This issue specifically affects versions 6.1.0.x before 6.1.0.3 CF26, 6.1.5.x before 6.1.5 CF26, 7.0.0.x before 7.0.0.2 CF21, and 8.0.0.x through 8.0.0.1 CF5 where the home substitution feature remains enabled. The vulnerability stems from insufficient input validation and sanitization of user-supplied data that flows through the portal's URI handling mechanisms, creating opportunities for malicious actors to inject carriage return line feed sequences into HTTP responses. This flaw operates under CWE-113 which specifically addresses improper neutralization of CRLF sequences in HTTP headers, making it a direct descendant of well-known HTTP response splitting vulnerabilities that have plagued web applications for decades.
The technical exploitation of this vulnerability occurs when authenticated users leverage the home substitution functionality to manipulate URI parameters that are subsequently processed without proper sanitization. When the uri.home.substitution feature is enabled, the portal processes user input in a manner that fails to properly escape or validate CRLF characters, allowing attackers to inject malicious headers into HTTP responses. The attack vector typically involves crafting specially formatted input that includes carriage return and line feed characters, which then get embedded into HTTP response headers. This enables attackers to perform HTTP response splitting attacks where they can inject additional HTTP headers or even manipulate the response content, potentially leading to session hijacking, cross-site scripting attacks, or cache poisoning scenarios.
The operational impact of this vulnerability extends beyond simple header injection, as it fundamentally compromises the integrity of HTTP responses generated by the WebSphere Portal server. Attackers can leverage this weakness to manipulate the response headers, potentially redirecting users to malicious sites, stealing session cookies, or injecting malicious content into the response stream. The authentication requirement reduces the attack surface compared to fully unauthenticated vulnerabilities, but the potential for lateral movement within the portal environment remains significant. Organizations using affected versions of IBM WebSphere Portal face risks of unauthorized access to sensitive portal resources, data exfiltration, and potential compromise of the entire portal infrastructure. This vulnerability directly maps to ATT&CK technique T1071.004 which covers application layer protocol manipulation and T1566 which addresses credential harvesting through social engineering or protocol manipulation.
Mitigation strategies for CVE-2013-2950 require immediate implementation of the vendor-provided security fixes and patches, specifically targeting the cumulative fixes mentioned in the vulnerability description. Organizations should disable the uri.home.substitution feature if it is not essential for business operations, as this immediately eliminates the attack vector. Input validation and sanitization measures must be strengthened to ensure all user-supplied data is properly escaped before processing, with particular attention to CRLF character handling. Network segmentation and monitoring solutions should be enhanced to detect anomalous HTTP response patterns that might indicate exploitation attempts. Regular security assessments should include verification of proper configuration settings and ensure that security patches are applied across all portal instances. The vulnerability highlights the importance of maintaining current security patches and implementing proper input validation at multiple layers of the application architecture, as the flaw exists in the core portal processing logic where user input transitions into HTTP response generation.