CVE-2001-0730 in HTTP Server
Summary
by MITRE
split-logfile in Apache 1.3.20 allows remote attackers to overwrite arbitrary files that end in the .log extension via an HTTP request with a / (slash) in the Host: header.
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Analysis
by VulDB Data Team • 10/04/2025
The vulnerability described in CVE-2001-0730 represents a critical file overwrite flaw in the Apache HTTP Server version 1.3.20, specifically within its split-logfile functionality. This issue arises from improper input validation in how the server processes the Host header field in HTTP requests, creating a path traversal condition that can be exploited by remote attackers. The vulnerability is particularly dangerous because it allows an attacker to target any file that ends with the .log extension, effectively enabling arbitrary file overwrite operations across the system.
The technical root cause of this vulnerability stems from the way Apache 1.3.20 handles the Host header parameter when processing split-logfile operations. When an attacker crafts an HTTP request containing a forward slash character within the Host header field, the server fails to properly sanitize this input before using it to construct file paths for log file operations. This improper validation creates a path traversal condition where the malicious input can manipulate the intended file destination, allowing the attacker to specify arbitrary file paths that end with .log extensions. The vulnerability is classified under CWE-22 as a path traversal weakness, where insufficient input sanitization leads to unauthorized file system access and modification.
The operational impact of this vulnerability is severe and far-reaching for any system running the affected Apache version. Attackers can leverage this flaw to overwrite critical system log files, potentially disrupting system monitoring and forensic analysis capabilities. More dangerously, the vulnerability could enable attackers to overwrite configuration files, executable binaries, or other sensitive system components that happen to have .log extensions, leading to potential system compromise or denial of service conditions. The remote nature of this attack means that exploitation can occur from any network location without requiring local system access, making it particularly attractive to malicious actors seeking to maintain persistent access to target systems. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1070 for indicator removal, as attackers can use this capability to manipulate system logs and hide their activities.
Mitigation strategies for this vulnerability require immediate action including upgrading to a patched version of Apache HTTP Server, as version 1.3.20 was superseded by versions that addressed this specific input validation flaw. System administrators should implement network-level restrictions to limit access to log file operations and consider implementing proper input validation at the application level to prevent slash characters from being processed in Host header fields. Additionally, organizations should review and harden their logging configurations to ensure that log files are stored in secure directories with appropriate access controls, and implement regular monitoring for unauthorized file modifications. The vulnerability also underscores the importance of following secure coding practices and conducting thorough input validation to prevent similar path traversal issues in web applications.