CVE-2002-1694 in IIS
Summary
by MITRE
Microsoft Internet Information Server (IIS) 4.0 opens log files with FILE_SHARE_READ and FILE_SHARE_WRITE permissions, which could allow remote attackers to modify the log file contents while IIS is running.
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Analysis
by VulDB Data Team • 04/19/2019
Microsoft Internet Information Server version 4.0 suffers from a critical file permission vulnerability that stems from its improper handling of log file access controls during runtime operations. The flaw manifests when IIS 4.0 opens its log files with overly permissive FILE_SHARE_READ and FILE_SHARE_WRITE access flags, creating a window of opportunity for malicious actors to manipulate log data while the web server remains active. This vulnerability directly relates to CWE-276, which addresses incorrect permissions for critical resources, and represents a classic example of inadequate access control implementation in server-side applications.
The technical exploitation of this vulnerability occurs through the manipulation of file sharing permissions that are established when IIS initializes its logging mechanisms. When the web server process opens log files with both read and write sharing capabilities, it inadvertently allows concurrent access from external processes that may not have proper authentication or authorization credentials. Attackers can leverage this weakness by creating malicious processes that attempt to access the same log files, potentially overwriting or corrupting log entries, injecting malicious data, or even preventing legitimate logging operations from completing successfully. This issue aligns with ATT&CK technique T1562.006, which covers "Impairing Security Tools" through file permission manipulation.
The operational impact of this vulnerability extends beyond simple data corruption, as it fundamentally undermines the integrity and reliability of system logging mechanisms that are critical for security monitoring, forensic analysis, and compliance auditing. When log files become tampered with or modified during active server operations, security teams lose confidence in their audit trails, potentially masking actual security incidents or allowing attackers to cover their tracks more effectively. The vulnerability affects the availability and integrity of logging data, which serves as a fundamental security control for detecting unauthorized access attempts, tracking system changes, and maintaining compliance with regulatory requirements such as those outlined in ISO/IEC 27001 and NIST cybersecurity frameworks.
Mitigation strategies for this vulnerability require immediate implementation of proper file access controls and system hardening measures. Organizations should ensure that IIS 4.0 installations utilize restrictive file sharing permissions that prevent unauthorized modification of log files during server operation. The recommended approach involves configuring log file access to use exclusive access modes or implementing proper file locking mechanisms that prevent concurrent write operations. System administrators should also consider implementing file integrity monitoring solutions and regular log file verification procedures to detect potential tampering. Additionally, upgrading to supported versions of IIS that properly implement secure file access controls represents the most effective long-term solution, as Microsoft has since addressed this specific vulnerability in subsequent releases of their web server software.