CVE-2016-1338 in TelePresence Video Communication Server
Summary
by MITRE
Cisco TelePresence Video Communication Server (VCS) X8.5.1 and X8.5.2 allows remote authenticated users to cause a denial of service (VoIP outage) via a crafted SIP message, aka Bug ID CSCuu43026.
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Analysis
by VulDB Data Team • 02/01/2019
The vulnerability identified as CVE-2016-1338 affects Cisco TelePresence Video Communication Server versions X8.5.1 and X8.5.2, representing a significant security flaw that enables remote authenticated attackers to disrupt voice over internet protocol services. This issue specifically targets the SIP messaging protocol implementation within the VCS platform, creating a pathway for malicious actors to induce system-wide VoIP outages. The vulnerability operates through a crafted SIP message that, when processed by the affected server, triggers an unexpected behavior leading to service disruption.
The technical implementation of this vulnerability resides in the improper handling of SIP messages within the Cisco VCS software stack. When an authenticated user sends a specially crafted SIP message to the server, the system fails to properly validate or sanitize the incoming data structure, resulting in a condition where the server becomes unresponsive or crashes. This flaw falls under the category of input validation issues that can be classified as CWE-20, which represents "Improper Input Validation" in the Common Weakness Enumeration framework. The vulnerability demonstrates how insufficient data sanitization can lead to system instability and service disruption in communication platforms.
The operational impact of CVE-2016-1338 extends beyond simple service interruption to encompass broader business continuity concerns for organizations relying on Cisco VCS for their video conferencing infrastructure. A successful exploitation of this vulnerability can result in complete VoIP service outages, affecting critical business communications and collaboration workflows. From an attacker perspective, this vulnerability operates through the ATT&CK framework's privilege escalation and denial of service techniques, allowing remote authenticated adversaries to leverage their existing access credentials to cause significant disruption. The attack vector requires only network access and valid authentication credentials, making it particularly dangerous in environments where administrative privileges are compromised or where credential theft occurs through phishing or other means.
Organizations affected by this vulnerability should prioritize immediate remediation through official Cisco security patches and updates. The recommended mitigation strategy involves applying the latest security patches provided by Cisco, which address the input validation flaw in the SIP message handling mechanism. Network segmentation and access controls should be implemented to limit the attack surface, while monitoring systems should be configured to detect unusual SIP traffic patterns that might indicate exploitation attempts. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in the broader communication infrastructure. The vulnerability highlights the importance of maintaining up-to-date security measures and demonstrates how even authenticated access can be weaponized to cause significant operational disruption in enterprise communication systems.