CVE-2016-1400 in TelePresence Video Communications Server
Summary
by MITRE
Cisco TelePresence Video Communications Server (VCS) X8.x before X8.7.2 allows remote attackers to cause a denial of service (service disruption) via a crafted URI in a SIP header, aka Bug ID CSCuy43258.
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Analysis
by VulDB Data Team • 08/22/2022
The Cisco TelePresence Video Communications Server X8.x vulnerability identified as CVE-2016-1400 represents a critical denial of service flaw that specifically targets the SIP (Session Initiation Protocol) processing capabilities of the VCS platform. This vulnerability affects versions prior to X8.7.2 and stems from improper input validation within the SIP header processing mechanism, creating an exploitable condition that can be leveraged by remote attackers to disrupt critical video communication services. The flaw manifests when the system encounters a specially crafted URI within a SIP header, which triggers an unexpected system behavior leading to service disruption.
The technical implementation of this vulnerability resides in the VCS's handling of malformed URI data within SIP messages, which falls under the category of improper input validation as classified by CWE-20. When the system processes the crafted URI, it fails to properly sanitize or validate the input before attempting to parse or utilize the data, resulting in a condition where the processing routine becomes unstable or crashes. This behavior aligns with ATT&CK technique T1499.004 which describes denial of service through resource exhaustion or system instability. The vulnerability exploits the fundamental trust placed in SIP header data, where the system assumes valid formatting without sufficient validation checks.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the integrity of video communication networks that rely on Cisco VCS platforms. Organizations utilizing these systems for critical business communications, healthcare applications, or educational video conferencing may experience significant service interruptions that can last from minutes to hours depending on the recovery process. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter without requiring physical access or authentication credentials, making it particularly dangerous for organizations with limited network segmentation. This vulnerability directly affects the availability component of the CIA triad and can be classified under ATT&CK technique T1486 which involves data manipulation or system disruption.
Mitigation strategies for this vulnerability require immediate implementation of the vendor-provided security patches and updates, specifically targeting the X8.7.2 release or higher. Network administrators should also implement SIP header filtering and validation mechanisms at network boundaries to prevent malformed URI data from reaching the VCS systems. Additionally, monitoring systems should be configured to detect unusual SIP traffic patterns that might indicate exploitation attempts, with alerts configured for abnormal URI formats. The remediation process should include comprehensive testing of the updated systems to ensure that the patch does not introduce compatibility issues with existing video communication protocols and services. Organizations should also consider implementing network segmentation strategies to limit the potential impact of such vulnerabilities and maintain detailed logs of SIP traffic for forensic analysis purposes.