CVE-2017-6758 in Unified Communications Manager
Summary
by MITRE
A vulnerability in the web framework of Cisco Unified Communications Manager 11.5(1.10000.6) could allow an authenticated, remote attacker to access arbitrary files in the context of the web root directory structure on an affected device. The vulnerability is due to insufficient input validation by the affected software. An attacker could exploit this vulnerability by using directory traversal techniques to read files in the web root directory structure on the Cisco Unified Communications Manager filesystem. Cisco Bug IDs: CSCve13796.
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Analysis
by VulDB Data Team • 01/07/2021
The vulnerability identified as CVE-2017-6758 resides within the web framework of Cisco Unified Communications Manager version 11.5(1.10000.6) and represents a critical directory traversal flaw that enables authenticated remote attackers to access arbitrary files within the web root directory structure. This vulnerability stems from inadequate input validation mechanisms implemented by the affected software, creating a pathway for malicious actors to bypass normal access controls and retrieve sensitive data from the system's file system. The flaw specifically manifests when the application fails to properly sanitize user-supplied input before processing file requests, allowing attackers to manipulate path references and navigate to unintended directories. The vulnerability affects Cisco Unified Communications Manager deployments where the web framework is enabled and accessible, potentially exposing critical system files, configuration data, and potentially sensitive user information to unauthorized access.
The technical exploitation of this vulnerability follows standard directory traversal attack patterns where an authenticated attacker crafts malicious requests containing sequences such as "../" or similar path manipulation techniques to traverse upward through the directory structure. When the web framework processes these malformed requests without proper validation, it executes the file access operations within the context of the web root directory, effectively allowing the attacker to read files that should normally be restricted. The vulnerability specifically impacts the web root directory structure, which typically contains web application files, configuration settings, and potentially database connection details that could be leveraged for further exploitation. Attackers could potentially access sensitive files such as log files, configuration files, or even application source code that might contain hard-coded credentials or other exploitable information.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to gain insights into the system's internal structure and potentially access files containing sensitive configuration data or credentials. The authenticated nature of the attack means that an attacker must first establish valid credentials to the system, but once achieved, the ability to traverse directories and access arbitrary files significantly increases the potential damage. This vulnerability could be particularly dangerous in environments where the Unified Communications Manager serves as a central communication hub, as it might expose call logs, user information, or integration details that could be used for social engineering attacks or further system compromise. The vulnerability's presence in the web framework component also suggests potential for cascading effects if the attacker can access files that contain database connection strings or other system integration details.
Organizations affected by this vulnerability should implement immediate mitigations including applying the official Cisco security patches released to address the directory traversal flaw. The patching process should involve updating the Cisco Unified Communications Manager software to a version that includes proper input validation mechanisms and sanitization of user-supplied paths. Network segmentation and access control measures should be strengthened to limit the attack surface, ensuring that only authorized personnel can access the web framework components. Additionally, implementing web application firewalls and monitoring for suspicious directory traversal patterns can help detect and prevent exploitation attempts. The vulnerability aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as the successful exploitation could lead to unauthorized access to sensitive system information and potentially facilitate further lateral movement within the network environment. Regular security assessments and input validation reviews should be conducted to prevent similar vulnerabilities from emerging in other components of the unified communications infrastructure.