CVE-2006-1078 in thttpd
Summary
by MITRE
Multiple buffer overflows in htpasswd, as used in Acme thttpd 2.25b, and possibly other products such as Apache, might allow local users to gain privileges via (1) a long command line argument and (2) a long line in a file. 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 • 01/17/2025
The vulnerability identified as CVE-2006-1078 represents a critical buffer overflow issue within the htpasswd utility that forms part of the Acme thttpd 2.25b web server implementation. This flaw manifests in two distinct attack vectors that exploit insufficient input validation mechanisms within the command line argument processing and file line handling components of the utility. The buffer overflow conditions occur when the utility processes excessively long command line arguments or when parsing lines exceeding predetermined length limits from input files, creating opportunities for arbitrary code execution and privilege escalation.
The technical implementation of this vulnerability stems from inadequate bounds checking within the htpasswd utility's string handling routines. When processing command line arguments, the utility fails to properly validate the length of input parameters before copying them into fixed-size buffers, resulting in memory corruption that can be exploited by maliciously crafted inputs. Similarly, when reading from password files, the utility does not enforce proper line length limitations, allowing attackers to craft input files containing excessively long lines that trigger buffer overflow conditions. This vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which addresses stack-based buffer overflow scenarios. The flaw demonstrates characteristics consistent with the attack patterns documented in the MITRE ATT&CK framework under technique T1068, which covers privilege escalation through local exploitation.
The operational impact of this vulnerability extends beyond the immediate scope of the thttpd implementation, as the issue affects other web server products including Apache that incorporate similar htpasswd functionality. Attackers can leverage these buffer overflow conditions to execute arbitrary code with elevated privileges, potentially compromising the entire system or server infrastructure. The local privilege escalation aspect of this vulnerability is particularly concerning as it allows attackers to gain higher-level system access without requiring network-based exploitation. The vulnerability's exploitation potential increases when considering configurations where htpasswd might be executed with elevated privileges or when integrated into systems that provide remote access to password file management functions. The security implications are further amplified by the fact that these buffer overflows can be triggered through multiple vectors, increasing the attack surface and making detection more challenging for system administrators.
Mitigation strategies for CVE-2006-1078 should focus on immediate patching of affected software versions and implementation of input validation controls. System administrators should ensure that all instances of htpasswd are updated to versions that properly validate input lengths and implement robust buffer management practices. The recommended approach includes applying security patches from software vendors, implementing strict input validation at the application level, and configuring systems to limit the maximum length of command line arguments and file input lines. Additionally, security monitoring should be enhanced to detect anomalous command line inputs or file content patterns that might indicate attempted exploitation. Organizations should also consider implementing privilege separation mechanisms to ensure that htpasswd utilities are not executed with unnecessary elevated privileges, thereby reducing the potential impact of successful exploitation attempts. The vulnerability highlights the importance of proper input validation and buffer management in security-critical applications, emphasizing the need for comprehensive code review processes and adherence to secure coding practices as outlined in industry standards and best practices.