CVE-2001-1191 in Tivoli Secureway Policy Director
Summary
by MITRE
WebSeal in IBM Tivoli SecureWay Policy Director 3.8 allows remote attackers to cause a denial of service (crash) via a URL that ends in %2e.
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Analysis
by VulDB Data Team • 05/11/2019
The vulnerability identified as CVE-2001-1191 affects IBM Tivoli SecureWay Policy Director version 3.8, specifically targeting the WebSeal component that serves as a web application firewall and policy enforcement point. This issue represents a classic denial of service vulnerability that exploits improper input handling within the web server component. The flaw manifests when a remote attacker crafts a malicious URL that terminates with the URL-encoded period character %2e, which triggers an abnormal termination of the WebSeal service.
The technical root cause of this vulnerability stems from inadequate input validation and parsing logic within the WebSeal module. When processing HTTP requests containing URLs ending with %2e, the system fails to properly handle the encoded character, leading to a crash condition that results in complete service unavailability. This type of vulnerability falls under the category of improper input validation as classified by CWE-20, where the application does not adequately validate or sanitize user-supplied data before processing. The issue demonstrates a lack of proper boundary checking and error handling mechanisms that should be implemented to prevent malformed input from causing system instability.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by remote attackers without authentication requirements, making it particularly dangerous in production environments. Organizations relying on WebSeal for security policy enforcement face potential business interruption and service degradation when this vulnerability is exploited. The crash condition affects the entire WebSeal service, potentially impacting multiple applications and services that depend on the policy director for access control and security enforcement. This vulnerability aligns with ATT&CK technique T1499.004 for network denial of service, where adversaries exploit weaknesses in network infrastructure components to disrupt availability.
Mitigation strategies for this vulnerability should include immediate application of IBM security patches and updates specifically addressing this issue in the Tivoli SecureWay Policy Director 3.8 release. Network administrators should implement additional monitoring and alerting mechanisms to detect unusual traffic patterns that may indicate exploitation attempts. Input filtering and sanitization measures should be enhanced at the network perimeter to prevent malformed URLs from reaching the vulnerable WebSeal component. Organizations should also consider implementing redundant security infrastructure to maintain service availability during potential exploitation events. The vulnerability highlights the importance of proper input validation and robust error handling in security appliances, emphasizing that even minor parsing inconsistencies can lead to significant service disruptions. This issue serves as a reminder of the critical need for thorough testing of input handling mechanisms in security products, particularly those handling HTTP traffic and URL parsing operations.