CVE-2017-6794 in Meeting Server
Summary
by MITRE
A vulnerability in the CLI command-parsing code of Cisco Meeting Server could allow an authenticated, local attacker to perform command injection and escalate their privileges to root. The attacker must first authenticate to the application with valid administrator credentials. The vulnerability is due to insufficient validation of user-supplied input at the CLI for certain commands. An attacker could exploit this vulnerability by authenticating to the affected application and submitting a crafted CLI command for execution at the Cisco Meeting Server CLI. An exploit could allow the attacker to perform command injection and escalate their privilege level to root. Vulnerable Products: This vulnerability exists in Cisco Meeting Server software versions prior to and including 2.0, 2.1, and 2.2. Cisco Bug IDs: CSCvf53830.
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Analysis
by VulDB Data Team • 01/11/2021
The vulnerability identified as CVE-2017-6794 represents a critical command injection flaw within the Cisco Meeting Server's command-line interface implementation. This security weakness resides in the CLI command-parsing code where insufficient input validation mechanisms fail to properly sanitize user-supplied data before processing. The vulnerability specifically affects Cisco Meeting Server software versions up to and including 2.0, 2.1, and 2.2, creating a persistent risk for organizations utilizing these older releases. The flaw operates at the application layer where legitimate administrative commands are processed, making it particularly dangerous as it requires only valid administrator credentials to exploit rather than elevated privileges or complex attack vectors.
The technical exploitation of this vulnerability follows a well-defined pattern where an authenticated attacker with administrative privileges can craft malicious CLI commands that bypass input validation checks. This insufficient validation creates a pathway for command injection attacks, allowing the attacker to execute arbitrary commands with the highest level of system privileges. The vulnerability's impact extends beyond simple privilege escalation as it enables full system compromise through root-level command execution. The flaw essentially allows attackers to manipulate the CLI's command processing logic by injecting malicious payloads that are subsequently executed with elevated privileges, effectively granting complete control over the affected system.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on Cisco Meeting Server for their collaboration infrastructure. The requirement for valid administrator credentials means that the attack vector is more constrained than typical remote exploits, but the potential impact remains severe as it allows for complete system compromise. The vulnerability affects the core administrative interface of the system, making it a prime target for attackers seeking persistent access or system takeover. Organizations using vulnerable versions face the risk of unauthorized data access, system modification, and potential use as a foothold for broader network infiltration attacks.
Security practitioners should recognize this vulnerability as a classic example of CWE-77 command injection, where user-supplied data is improperly handled within a command context. The ATT&CK framework categorizes this as privilege escalation through command execution, with techniques such as command injection and privilege escalation being directly applicable. The vulnerability demonstrates the critical importance of input validation and proper sanitization of user-supplied data in administrative interfaces. Organizations should immediately implement mitigations including patching to versions that address the vulnerability, implementing network segmentation to limit access to administrative interfaces, and establishing robust monitoring for suspicious CLI activity. The Cisco Bug ID CSCvf53830 specifically identifies this issue and provides guidance for affected systems, though the most effective mitigation remains the immediate upgrade to patched software versions that contain proper input validation mechanisms.
The broader implications of this vulnerability highlight the importance of maintaining up-to-date security patches and the dangers of running legacy software versions in production environments. Organizations should conduct comprehensive vulnerability assessments to identify all instances of affected Cisco Meeting Server software and implement layered security controls including privileged access management, regular security audits, and continuous monitoring of administrative interfaces for unauthorized access attempts. The vulnerability serves as a reminder that even authenticated administrative interfaces require robust security controls to prevent privilege escalation attacks that can result in complete system compromise.