CVE-2002-2257 in LIBCGI
Summary
by MITRE
Stack-based buffer overflow in the parse_field function in cgi_lib.c for LIBCGI 1.0.2 and 1.0.3 allows remote attackers to execute arbitrary code via a long argument.
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Analysis
by VulDB Data Team • 06/12/2018
The vulnerability identified as CVE-2002-2257 represents a critical stack-based buffer overflow flaw within the LIBCGI 1.0.2 and 1.0.3 library components. This issue specifically affects the parse_field function located in the cgi_lib.c source file, which forms a fundamental component of web application frameworks that process common gateway interface requests. The vulnerability arises from inadequate input validation mechanisms that fail to properly constrain the length of arguments passed to the parsing function, creating an exploitable condition where maliciously crafted input can overwrite adjacent memory locations on the stack.
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 stack memory. The flaw occurs during the processing of HTTP request parameters through the cgi_lib library, where the parse_field function does not adequately validate the length of incoming argument data before copying it into fixed-size stack buffers. This allows remote attackers to craft specially formatted input strings that exceed the allocated buffer space, resulting in memory corruption that can be exploited to execute arbitrary code with the privileges of the affected web application process. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1203, where adversaries leverage input validation weaknesses to achieve code execution through buffer overflow mechanisms.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise when exploited successfully. Web applications utilizing affected versions of LIBCGI become vulnerable to remote code execution attacks, potentially allowing attackers to gain unauthorized access to server resources, escalate privileges, and establish persistent access to the compromised system. The vulnerability affects any application that relies on the vulnerable library for processing web form data, making it particularly dangerous in web server environments where CGI scripts are commonly deployed. The exploitation requires minimal privileges and can be automated, making it an attractive target for attackers seeking to compromise web infrastructure. Organizations running vulnerable systems face significant risk of data breaches, service disruption, and potential lateral movement within their network infrastructure.
Mitigation strategies for CVE-2002-2257 require immediate action to address the root cause through software updates and code modifications. The primary recommendation involves upgrading to a patched version of LIBCGI that implements proper bounds checking in the parse_field function, ensuring that input arguments are validated against predetermined maximum lengths before buffer operations occur. Additionally, input sanitization measures should be implemented at multiple layers including web application firewalls, proxy servers, and application-level validation to provide defense-in-depth protection. The implementation of stack protection mechanisms such as stack canaries and address space layout randomization can help mitigate exploitation attempts even if the underlying vulnerability persists. System administrators should also conduct comprehensive vulnerability assessments to identify all instances of the affected library throughout their infrastructure, as the vulnerability may be present in multiple applications and services that utilize CGI processing capabilities.