CVE-2006-6259 in AlternC
Summary
by MITRE
Multiple directory traversal vulnerabilities in (a) class/functions.php and (b) class/m_bro.php in AlternC 0.9.5 and earlier allow remote attackers to (1) create arbitrary files and directories via a .. (dot dot) in the "create name" field and (2) read arbitrary files via a .. (dot dot) in the "web root" field when configuring a subdomain.
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Analysis
by VulDB Data Team • 08/09/2018
The vulnerability CVE-2006-6259 represents a critical directory traversal flaw affecting AlternC version 0.9.5 and earlier, which is a web hosting control panel designed to simplify server administration for shared hosting environments. This vulnerability manifests in two distinct locations within the AlternC codebase, specifically in the class/functions.php and class/m_bro.php files, both of which handle file system operations and subdomain configuration processes. The flaw stems from inadequate input validation and sanitization mechanisms that fail to properly restrict directory traversal sequences, allowing malicious actors to exploit the system through carefully crafted requests containing dot-dot sequences.
The technical implementation of this vulnerability exploits the fundamental weakness in how the system processes user-supplied input for file creation and path resolution. When attackers manipulate the "create name" field with directory traversal sequences, they can bypass normal file system access controls to create arbitrary files and directories outside of intended boundaries. Similarly, when manipulating the "web root" field during subdomain configuration, attackers can read arbitrary files from the server's file system, potentially accessing sensitive configuration files, user data, or system resources. This dual nature of the vulnerability enables both arbitrary file creation and arbitrary file reading capabilities, significantly expanding the potential attack surface.
The operational impact of CVE-2006-6259 extends far beyond simple unauthorized access, as it provides attackers with the ability to establish persistent footholds within the hosting environment. Through arbitrary file creation, attackers can deploy web shells, backdoors, or malicious scripts that maintain access even after system restarts. The arbitrary file reading capability allows for information disclosure attacks that can expose database credentials, configuration files, user passwords, and other sensitive data. This vulnerability directly relates to CWE-22, which describes improper limitation of a pathname to a restricted directory, and represents a classic example of path traversal attacks that have been documented in the cybersecurity community for decades. The vulnerability's impact is particularly severe in shared hosting environments where multiple users operate within the same system, as it can enable privilege escalation and cross-contamination of user data.
Mitigation strategies for this vulnerability must address both the immediate code-level fixes and broader architectural security considerations. The primary solution involves implementing strict input validation and sanitization for all user-supplied paths, particularly those used in file system operations. This includes normalizing pathnames, removing or encoding special characters like dots and slashes, and implementing whitelist-based validation for acceptable file names and directory structures. Security controls should enforce proper directory boundaries using absolute path resolution and ensure that all file system operations occur within designated safe directories. Organizations should also implement the principle of least privilege, restricting file system access to only necessary operations and using secure coding practices that prevent path traversal attacks. Additionally, regular security audits and input validation testing should be conducted to identify similar vulnerabilities in other parts of the system, as this type of flaw often indicates broader security design issues that may affect other components of the hosting platform. The vulnerability demonstrates the critical importance of secure input handling in web applications and aligns with ATT&CK technique T1059.007 for command and script injection, as successful exploitation can lead to full system compromise through the execution of malicious code in the compromised hosting environment.