CVE-2002-1658 in HTTP Server
Summary
by MITRE
Buffer overflow in htdigest in Apache 1.3.26 and 1.3.27 may allow attackers to execute arbitrary code via a long user argument. NOTE: since htdigest is normally only locally accessible and not setuid or setgid, there are few attack vectors which would lead to an escalation of privileges, unless htdigest is executed from a CGI program. Therefore this may not be a vulnerability.
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Analysis
by VulDB Data Team • 04/19/2019
The vulnerability identified as CVE-2002-1658 represents a critical buffer overflow flaw within the htdigest utility of Apache HTTP Server versions 1.3.26 and 1.3.27. This buffer overflow occurs when processing user arguments that exceed the allocated buffer size, creating a potential pathway for malicious code execution. The htdigest utility is specifically designed to create and manage password files for HTTP Basic Authentication, making it an integral component in web server security configurations. The flaw manifests when an attacker provides an excessively long user argument parameter that overflows the designated memory buffer, potentially allowing for arbitrary code execution on the target system. This vulnerability operates under CWE-121, which classifies buffer overflow conditions where insufficient bounds checking allows data to overwrite adjacent memory locations.
The technical exploitation of this vulnerability requires careful manipulation of input parameters to trigger the buffer overflow condition. When htdigest processes a user argument that surpasses the predetermined buffer limits, the excess data overflows into adjacent memory segments, potentially corrupting program execution flow or allowing attackers to inject and execute malicious code. The attack vector becomes particularly concerning when htdigest is executed in a CGI context where it might be invoked with user-supplied input, creating opportunities for privilege escalation. Although the utility is typically designed for local administrative use and lacks setuid or setgid permissions that would normally provide elevated privileges, the vulnerability becomes more severe when htdigest is executed through CGI programs or other contexts where it might inherit elevated permissions from the execution environment.
The operational impact of CVE-2002-1658 extends beyond simple code execution to encompass potential system compromise and unauthorized access to protected resources. Even though the vulnerability description notes that htdigest is normally locally accessible and not setuid or setgid, the potential for exploitation increases significantly when the utility is improperly configured or executed within web server contexts. Attackers could leverage this vulnerability to gain unauthorized access to web server authentication files, potentially compromising entire web applications that rely on Basic Authentication mechanisms. The vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', demonstrating how buffer overflows can be weaponized to achieve elevated system privileges, particularly when combined with improper execution contexts.
Mitigation strategies for CVE-2002-1658 should focus on immediate version upgrades to Apache 1.3.28 or later, which contain patches addressing the buffer overflow condition in htdigest. System administrators must ensure that all instances of htdigest are properly configured to prevent execution in CGI contexts where user input could be processed without proper validation. Additionally, implementing proper input validation and bounds checking mechanisms within any custom applications that invoke htdigest would significantly reduce the attack surface. The vulnerability serves as a reminder of the critical importance of input validation in security-critical utilities and demonstrates how seemingly minor flaws in authentication utilities can have significant implications for overall system security. Organizations should conduct thorough audits of their web server configurations to identify any instances where htdigest might be executed in contexts that could expose the system to this vulnerability, particularly in environments where CGI execution is permitted.