CVE-2015-7435 in Tivoli Common Reporting
Summary
by MITRE
IBM Tivoli Common Reporting (TCR) 2.1 before IF14, 2.1.1 before IF22, 2.1.1.2 before IF9, 3.1.0.0 through 3.1.2 as used in Cognos Business Intelligence before 10.2 IF16, and 3.1.2.1 as used in Cognos Business Intelligence before 10.2.1.1 IF12 allows local users to bypass the Cognos Application Firewall (CAF) protection mechanism via leading whitespace in the BackURL field.
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Analysis
by VulDB Data Team • 05/26/2018
The vulnerability identified as CVE-2015-7435 represents a critical security flaw in IBM Tivoli Common Reporting and Cognos Business Intelligence products that affects multiple versions across different release streams. This weakness stems from improper validation of the BackURL parameter within the authentication flow, specifically when leading whitespace characters are present in the URL field. The issue allows malicious actors to bypass the Cognos Application Firewall protection mechanism, which is designed to prevent unauthorized redirection attempts and maintain application security boundaries.
The technical root cause of this vulnerability lies in the insufficient input sanitization and validation processes implemented within the Cognos Application Firewall. When a user attempts to authenticate and provides a BackURL parameter containing leading whitespace characters, the system fails to properly normalize or validate this input before processing the redirection. This behavior creates a bypass opportunity where attackers can manipulate the URL to redirect users to malicious destinations while appearing to originate from legitimate sources within the application framework. The vulnerability is classified under CWE-20 as "Improper Input Validation" and specifically relates to improper handling of whitespace characters in URL validation.
The operational impact of this vulnerability is significant as it undermines the fundamental security controls designed to protect against open redirect attacks and potential phishing scenarios. Attackers can exploit this weakness to redirect users to malicious websites while maintaining the appearance of legitimate application behavior, potentially leading to credential theft, data exfiltration, or further exploitation within the target environment. The vulnerability affects organizations using various versions of IBM Tivoli Common Reporting and Cognos Business Intelligence, particularly those that have not applied the necessary interim fixes or service packs. This creates widespread exposure across enterprise environments where these reporting tools are deployed, as the flaw exists in multiple release versions and service pack combinations.
Organizations affected by this vulnerability should immediately implement the vendor-provided patches and interim fixes for their specific product versions to address the Cognos Application Firewall bypass. System administrators should also consider implementing additional network-level controls and monitoring for suspicious redirection patterns in authentication flows. The remediation process requires careful attention to ensure that all affected versions receive proper updates, including the specific interim fixes mentioned in the vulnerability description for each product line. Security teams should conduct comprehensive vulnerability assessments to identify all instances of affected software within their environments and establish monitoring procedures to detect potential exploitation attempts. This vulnerability demonstrates the critical importance of proper input validation and the potential consequences of inadequate sanitization of user-provided parameters in security-critical application components.