CVE-2005-1086 in AN-HTTPd
Summary
by MITRE
Buffer overflow in the cmdIS.DLL plugin for AN HTTPD Server 1.42n allows remote attackers to execute arbitrary code via an HTTP request with a long User-Agent header.
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Analysis
by VulDB Data Team • 07/07/2018
The vulnerability identified as CVE-2005-1086 represents a critical buffer overflow flaw within the cmdIS.DLL plugin of AN HTTPD Server version 1.42n. This issue arises from insufficient input validation mechanisms that fail to properly handle excessively long User-Agent headers in HTTP requests. The vulnerability exists at the application layer where the web server processes incoming HTTP requests and specifically affects the plugin component responsible for handling certain command execution functionalities. The buffer overflow occurs when the server attempts to store a User-Agent header exceeding the allocated buffer space, leading to memory corruption that can be exploited by malicious actors.
The technical exploitation of this vulnerability follows a classic buffer overflow attack pattern where an attacker crafts a specially formatted HTTP request containing an extended User-Agent header that exceeds the predetermined buffer limits. When the AN HTTPD Server processes this request, the overflow corrupts adjacent memory locations, potentially overwriting critical program execution pointers or return addresses. This memory corruption can be manipulated to redirect program execution flow and ultimately allow remote code execution on the vulnerable system. The flaw specifically relates to CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows data to be written beyond the allocated buffer boundaries. The vulnerability demonstrates characteristics of CWE-787, which addresses out-of-bounds writes that occur when a buffer is accessed beyond its allocated size.
The operational impact of CVE-2005-1086 extends beyond simple remote code execution to encompass complete system compromise and potential denial of service conditions. An attacker who successfully exploits this vulnerability can gain unauthorized access to the web server system, potentially elevating privileges and establishing persistent access. The attack vector is particularly concerning as it requires no authentication and can be executed through standard HTTP traffic, making it highly accessible to remote threat actors. The vulnerability affects the availability and integrity of the web server service, as successful exploitation can lead to system crashes or unauthorized data manipulation. Organizations running AN HTTPD Server 1.42n are exposed to significant risk, as this vulnerability can be exploited by automated scanning tools and represents a common target for botnet-driven attacks.
Mitigation strategies for CVE-2005-1086 should prioritize immediate patching of the affected software components and implementation of network-level protections. The primary remediation involves upgrading to a patched version of AN HTTPD Server that includes proper input validation for User-Agent headers and implements buffer size limitations. Network administrators should deploy intrusion detection systems capable of identifying and blocking HTTP requests with suspiciously long User-Agent headers. Additionally, implementing application-level firewalls and web application firewalls can help filter malicious traffic before it reaches the vulnerable server components. Security configurations should include disabling unnecessary plugins and services, implementing strict input validation policies, and establishing monitoring procedures to detect anomalous traffic patterns. The ATT&CK framework categorizes this vulnerability under T1203, which covers exploitation of remote services, and T1059, which covers command and scripting interpreters, making it a significant concern for enterprise security postures. Organizations should also consider implementing network segmentation and privilege separation to limit the potential impact of successful exploitation.