CVE-2001-0820 in Ghttp
Summary
by MITRE
Buffer overflows in GazTek ghttpd 1.4 allows a remote attacker to execute arbitrary code via long arguments that are passed to (1) the Log function in util.c, or (2) serveconnection in protocol.c.
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Analysis
by VulDB Data Team • 10/04/2025
The vulnerability identified as CVE-2001-0820 represents a critical buffer overflow flaw in the GazTek ghttpd 1.4 web server implementation that exposes remote code execution capabilities to malicious actors. This vulnerability resides within the httpd server software's handling of user-supplied input parameters, specifically targeting two distinct code paths within the application's source code. The flaw manifests when the server processes excessively long arguments passed to either the Log function located in util.c or the serveconnection function found in protocol.c, creating conditions where memory boundaries are exceeded and potentially executable code can be injected into the process space.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The attack vector operates through network-based exploitation where remote adversaries can craft specially formatted HTTP requests containing extended argument strings that trigger the buffer overflow behavior. When the web server processes these malformed inputs, the excessive data overflows the allocated buffer space and can overwrite critical memory segments including return addresses, function pointers, or other control data structures within the program execution context.
From an operational perspective, this vulnerability presents a severe risk to systems running GazTek ghttpd 1.4 as it enables remote code execution without requiring authentication or prior access to the system. The impact extends beyond simple service disruption to potential complete system compromise, allowing attackers to execute arbitrary commands with the privileges of the web server process. This vulnerability directly maps to ATT&CK technique T1203, which involves the exploitation of software vulnerabilities to gain execution privileges, and T1059, which covers the use of command and scripting interpreters to execute malicious code. The attack surface is particularly concerning given that web servers typically operate with elevated privileges and may have access to sensitive system resources or databases.
The mitigation strategies for this vulnerability should prioritize immediate patching or upgrading to a version of GazTek ghttpd that addresses the buffer overflow conditions. Organizations should implement network-based restrictions to limit access to the affected web server and monitor for suspicious traffic patterns that may indicate exploitation attempts. Additional defensive measures include implementing input validation controls that limit the length of arguments passed to web server functions, deploying intrusion detection systems to identify malformed HTTP requests, and applying runtime protections such as stack canaries or address space layout randomization to make exploitation more difficult. Security teams should also conduct comprehensive vulnerability assessments to identify other potentially affected systems running similar versions of the software and ensure proper network segmentation to limit the potential impact of successful exploitation attempts.