CVE-2010-2840 in Unified Presence Server
Summary
by MITRE
The Presence Engine (PE) service in Cisco Unified Presence 6.x before 6.0(7) and 7.x before 7.0(8) does not properly handle an erroneous Contact field in the header of a SIP SUBSCRIBE message, which allows remote attackers to cause a denial of service (process failure) via a malformed message, aka Bug ID CSCtd39629.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/03/2017
The vulnerability described in CVE-2010-2840 affects Cisco Unified Presence 6.x versions prior to 6.0(7) and 7.x versions prior to 7.0(8) where the Presence Engine service fails to properly validate the Contact field within SIP SUBSCRIBE messages. This issue represents a classic input validation flaw that can be exploited to trigger unauthorized service disruption. The vulnerability specifically targets the SIP SUBSCRIBE message processing mechanism within the Cisco Unified Presence system, which is responsible for handling presence subscription requests from users and devices within the unified communications environment. The flaw exists in how the system processes the Contact header field, which is a standard component of SIP messages used to identify the contact information of the entity making the request.
The technical implementation of this vulnerability stems from inadequate error handling within the SIP message parsing logic of the Presence Engine service. When a malformed SIP SUBSCRIBE message containing an erroneous Contact field is received, the service does not gracefully handle the malformed input but instead fails to process the message properly, leading to process termination or system instability. This behavior aligns with CWE-20, which describes improper input validation, and represents a form of resource exhaustion attack that can be executed remotely without authentication. The vulnerability allows attackers to craft specific SIP messages that trigger the service to crash or restart, effectively causing a denial of service condition that impacts presence services for users within the Cisco Unified Presence environment. The attack vector is particularly concerning as it requires no privileged access and can be executed from any location that can reach the affected service.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the reliability and availability of unified communications within enterprise networks. When the Presence Engine service fails due to this vulnerability, users lose access to presence information such as availability status, call routing capabilities, and other real-time communication features that depend on the unified presence system. This can severely impact business operations where real-time communication and collaboration are critical. The vulnerability affects the core functionality of Cisco Unified Presence, which serves as a central component for managing user presence information across various communication platforms including IP phones, instant messaging clients, and unified communication applications. Organizations relying on these services for mission-critical operations may experience significant operational disruption when this vulnerability is exploited. The attack can be executed through standard network traffic without requiring specialized tools or deep technical knowledge, making it particularly dangerous for widespread exploitation.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems to the recommended versions 6.0(7) and 7.0(8) where the issue has been addressed through proper input validation and error handling mechanisms. Network administrators should implement monitoring solutions to detect anomalous SIP traffic patterns that may indicate exploitation attempts, particularly focusing on SUBSCRIBE messages with malformed Contact headers. The implementation of network access controls and firewall rules to restrict access to the affected service from untrusted networks can provide additional defense-in-depth measures. Security teams should also consider implementing intrusion detection systems that can identify and alert on suspicious SIP message patterns that match the vulnerability characteristics. Organizations should conduct thorough vulnerability assessments to identify all instances of affected Cisco Unified Presence installations within their network infrastructure and prioritize remediation efforts based on risk exposure. The fix typically involves enhanced input validation routines that properly handle malformed SIP headers and implement graceful error recovery mechanisms to prevent process termination when encountering unexpected input data patterns.