CVE-2002-0427 in Improved Mod Frontpage
Summary
by MITRE
Buffer overflows in fpexec in mod_frontpage before 1.6.1 may allow attackers to gain root privileges.
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Analysis
by VulDB Data Team • 09/17/2025
The vulnerability identified as CVE-2002-0427 represents a critical buffer overflow flaw within the fpexec component of mod_frontpage Apache module versions prior to 1.6.1. This issue resides in the FrontPage Extension module which was commonly used to provide web-based publishing capabilities for Microsoft FrontPage users. The buffer overflow occurs when the fpexec utility processes certain input parameters, specifically within the handling of command-line arguments that are passed to the system execution functions. The flaw allows an attacker to manipulate input data in a way that exceeds the allocated buffer space, potentially leading to arbitrary code execution. This vulnerability is particularly dangerous because it can be exploited to escalate privileges from a regular user account to root level access on the affected system.
The technical implementation of this buffer overflow stems from improper input validation and memory management within the fpexec utility. When the mod_frontpage module processes incoming requests, it passes user-supplied parameters directly to system calls without adequate bounds checking. The vulnerability manifests when an attacker crafts malicious input that overflows the fixed-size buffer allocated for storing command-line arguments. This overflow can overwrite adjacent memory locations including return addresses and control data, enabling attackers to redirect program execution flow. The flaw specifically affects systems where mod_frontpage is installed and enabled, making it a significant concern for web servers that support FrontPage Extensions. According to CWE classification, this represents a classic buffer overflow vulnerability categorized under CWE-121, which deals with stack-based buffer overflow conditions.
The operational impact of CVE-2002-0427 extends beyond simple privilege escalation to encompass full system compromise capabilities. Attackers who successfully exploit this vulnerability can gain root access to the web server, allowing them to install backdoors, modify system files, steal sensitive data, or establish persistent access to the compromised infrastructure. The vulnerability is particularly concerning because it requires no special privileges to exploit, making it accessible to any remote attacker who can submit malicious requests to the affected web server. This type of privilege escalation vulnerability directly maps to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and represents a common attack pattern used by threat actors to gain elevated system access. The impact is amplified in environments where web servers host sensitive applications or contain critical business data, as the compromise of a single server can lead to broader network infiltration.
Mitigation strategies for CVE-2002-0427 focus primarily on immediate patching and configuration hardening measures. Organizations should immediately upgrade to mod_frontpage version 1.6.1 or later, which includes proper input validation and buffer size checks that prevent the overflow condition. System administrators should also consider disabling the FrontPage Extensions entirely if they are not actively required, as this eliminates the attack surface entirely. Additional protective measures include implementing proper input sanitization at the web server level, configuring appropriate access controls to limit who can submit requests to the affected module, and monitoring system logs for suspicious activity. Network-level protections such as firewalls and intrusion detection systems can help detect and block exploitation attempts, while regular security audits should verify that the module is properly configured and that no unauthorized modifications have been made to the system. The vulnerability serves as a reminder of the importance of keeping web server components updated and the dangers of running legacy extensions that may contain unpatched security flaws.