CVE-2011-2538 in Video Communications Server
Summary
by MITRE
Cisco Video Communications Server (VCS) before X7.0.3 contains a command injection vulnerability which allows remote, authenticated attackers to execute arbitrary commands.
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Analysis
by VulDB Data Team • 10/30/2019
The Cisco Video Communications Server VCS vulnerability identified as CVE-2011-2538 represents a critical command injection flaw that affects versions prior to X7.0.3. This vulnerability resides within the server's handling of user input in specific administrative functions, creating a pathway for malicious actors to execute arbitrary code on the affected system. The flaw specifically manifests when the VCS processes certain command-line arguments or parameters without proper sanitization, allowing attackers to inject malicious commands that are then executed with the privileges of the affected service. This vulnerability is particularly concerning as it requires only authenticated access, meaning that an attacker who has obtained valid credentials can leverage this flaw to gain full control over the video communications server.
The technical implementation of this command injection vulnerability stems from inadequate input validation and sanitization within the VCS administrative interfaces. When legitimate users submit commands or parameters through the web-based management console or API endpoints, the system fails to properly escape or filter special characters that could be interpreted as shell commands. This allows an authenticated attacker to append malicious commands to legitimate requests, which are then processed by the underlying operating system. The vulnerability falls under CWE-77 as it represents a command injection weakness where user-supplied data is directly incorporated into system commands without proper validation or sanitization. The attack vector specifically targets the VCS's administrative functionality, making it particularly dangerous as it provides access to the core system operations and potentially allows for privilege escalation.
The operational impact of this vulnerability extends far beyond simple command execution, as it provides attackers with complete control over the affected VCS server. Once exploited, an attacker can manipulate video communication services, access sensitive configuration data, modify user accounts, and potentially use the compromised server as a pivot point for attacking other systems within the network. The vulnerability's remote nature means that attackers do not require physical access to the premises, and the authenticated requirement significantly reduces the attack surface compared to unauthenticated exploits. Organizations relying on Cisco VCS for critical video conferencing and communication services face substantial risk, as this vulnerability could lead to complete service disruption, data breaches, or unauthorized access to video communication sessions. The impact is particularly severe in enterprise environments where VCS servers often serve as central communication hubs.
Mitigation strategies for CVE-2011-2538 should prioritize immediate patching of affected systems to the Cisco X7.0.3 release or higher, as this represents the official fix for the command injection vulnerability. Network segmentation and access controls should be implemented to limit administrative access to the VCS server, ensuring that only authorized personnel with legitimate business needs can access the management interfaces. The principle of least privilege should be enforced, with administrative accounts having minimal necessary permissions and strong authentication mechanisms including multi-factor authentication. Regular security audits and monitoring of administrative access logs should be conducted to detect potential exploitation attempts. Organizations should also implement network intrusion detection systems that can identify suspicious command execution patterns and anomalous administrative activities. This vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, specifically focusing on the execution of system commands through vulnerable interfaces. The remediation process should include thorough testing of the patched software to ensure that the fix does not introduce compatibility issues with existing video communication services and configurations.