CVE-2006-1079 in httpd
Summary
by MITRE
htpasswd, as used in Acme thttpd 2.25b and possibly other products such as Apache, might allow local users to gain privileges via shell metacharacters in a command line argument, which is used in a call to the system function. NOTE: since htpasswd is normally installed as a non-setuid program, and the exploit is through command line options, perhaps this issue should not be included in CVE. However, if there are some typical or recommended configurations that use htpasswd with sudo privileges, or common products that access htpasswd remotely, then perhaps it should be included.
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Analysis
by VulDB Data Team • 07/20/2018
The vulnerability described in CVE-2006-1079 pertains to the htpasswd utility within the thttpd web server software version 2.25b and potentially other implementations including Apache. This issue represents a classic command injection vulnerability that arises from improper input validation when processing command line arguments. The flaw occurs because the htpasswd utility, when invoked with certain command line parameters, passes these arguments directly to the system function without adequate sanitization or escaping mechanisms. This design flaw creates a pathway for malicious users to inject shell metacharacters that can be interpreted and executed by the underlying operating system shell, potentially leading to unauthorized privilege escalation.
The technical nature of this vulnerability aligns with CWE-78, which specifically addresses "Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')". The vulnerability manifests when local users manipulate command line arguments passed to htpasswd, which are subsequently processed through a system call. This creates an attack surface where shell metacharacters such as semicolons, pipes, or backticks can be embedded in the input parameters, allowing attackers to execute arbitrary commands with the privileges of the user running the htpasswd utility. The risk is particularly concerning because htpasswd is often used in web server configurations for authentication management, and when integrated with other systems, it can potentially be leveraged for broader system compromise.
The operational impact of this vulnerability extends beyond simple command execution, as it can be exploited to escalate privileges and gain unauthorized access to system resources. While the vulnerability description notes that htpasswd is typically installed as a non-setuid program, the potential for exploitation increases significantly when the utility is used in configurations that grant it elevated privileges through sudo or other privilege escalation mechanisms. Attackers could leverage this vulnerability to execute malicious commands with higher privileges than intended, potentially compromising the entire system. The remote exploitation aspect becomes relevant when considering common web server configurations that might access htpasswd files or execute the utility as part of automated processes, creating opportunities for attackers to manipulate command line arguments through various attack vectors.
Mitigation strategies for this vulnerability should focus on input validation and sanitization practices that prevent shell metacharacters from being processed as command arguments. The recommended approach involves implementing proper argument escaping and validation mechanisms that ensure all input parameters are treated as data rather than executable commands. System administrators should verify that htpasswd is not being invoked with elevated privileges unless absolutely necessary, and that any usage of the utility in automated contexts properly sanitizes all input parameters. Additionally, organizations should consider implementing privilege separation mechanisms and regularly audit their web server configurations to ensure that authentication utilities are not being used in ways that could expose the system to command injection attacks. The vulnerability underscores the importance of following secure coding practices and the principle of least privilege in system administration, as detailed in various cybersecurity frameworks including those referenced by the ATT&CK framework for command and control operations.