CVE-2005-3559 in Asterisk
Summary
by MITRE
Directory traversal vulnerability in vmail.cgi in Asterisk 1.0.9 through 1.2.0-beta1 allows remote attackers to access WAV files via a .. (dot dot) in the folder parameter.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/26/2024
The vulnerability identified as CVE-2005-3559 represents a critical directory traversal flaw in the vmail.cgi component of Asterisk versions ranging from 1.0.9 through 1.2.0-beta1. This weakness resides within the voice mail system's web interface implementation where the folder parameter fails to properly validate user input, creating an opportunity for malicious actors to navigate outside the intended directory structure. The vulnerability specifically manifests when attackers manipulate the folder parameter using .. (dot dot) sequences to traverse up the directory hierarchy and access restricted files including WAV audio recordings that contain voice mail messages. This issue directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The attack vector operates through the web-based interface of the Asterisk voice mail system, making it accessible to remote attackers without requiring authentication or local system access.
The technical exploitation of this vulnerability enables attackers to bypass normal access controls and retrieve sensitive voice mail content that should remain protected within designated directories. When the vmail.cgi script processes a request containing a malicious folder parameter with directory traversal sequences, it fails to sanitize or validate the input before using it in file operations. This allows an attacker to construct paths that reference files outside the intended voice mail storage directories, potentially accessing not only WAV files but also configuration files, logs, or other sensitive data stored on the system. The impact extends beyond simple file access as voice mail content often contains confidential business communications, personal information, or sensitive operational details that could be exploited for social engineering attacks or corporate espionage. The vulnerability demonstrates a fundamental lack of input validation and proper path resolution mechanisms within the web interface component.
From an operational perspective, this vulnerability creates significant security risks for organizations relying on Asterisk for voice communication services, particularly those in regulated industries such as healthcare, finance, or government sectors where audio data privacy is paramount. The remote nature of the attack means that adversaries can exploit this weakness from anywhere on the internet without requiring physical access to the system or knowledge of internal network structures. Attackers can systematically enumerate voice mail directories and retrieve stored audio files, potentially building comprehensive archives of sensitive communications. The vulnerability also represents a potential entry point for further attacks, as access to voice mail files might reveal information about system configuration, user accounts, or communication patterns that could be leveraged in subsequent exploitation attempts. This makes the vulnerability particularly dangerous in environments where Asterisk systems are exposed to untrusted networks or where insufficient network segmentation exists.
Organizations should implement immediate mitigations including applying the latest security patches available from the Asterisk project, which would have addressed this directory traversal vulnerability through proper input validation and path sanitization. Network segmentation should be enforced to limit access to the affected web interface components, and firewalls should be configured to restrict access to the specific ports serving the vmail.cgi functionality. Input validation measures should be implemented at multiple layers including web application firewalls and application-level sanitization of all user-supplied parameters. The principle of least privilege should be applied by ensuring that the web interface runs with minimal necessary permissions and that file system access is restricted to only required directories. Additionally, organizations should conduct regular security assessments of their voice communication systems and implement monitoring solutions to detect anomalous access patterns that might indicate exploitation attempts. This vulnerability highlights the importance of secure coding practices and input validation in web applications, particularly those handling sensitive data, and aligns with ATT&CK technique T1071.004 for application layer protocol traffic shaping and T1190 for exploitation of remote services.