Cisco Unified Communications Manager contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Cisco Unified Communications Manager versions prior to 6.1(5), prior to 7.1(3a)su1, and prior to 8.0(1) contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability is due to errors in processing Skinny Client Control Protocol (SCCP) packets. An unauthenticated, remote attacker could exploit the vulnerability by sending a malicious SCCP packet to the targeted system. If an exploit is successful, the attacker could cause portions of the software to fail, resulting in a DoS condition.
Cisco has confirmed this vulnerability in a security advisory and released updated software.
The following Cisco Unified Communications Manager versions are vulnerable:
Versions prior to 6.1(5) Versions prior to 7.1(3a)su1 Versions prior to 8.0(1)
To exploit the vulnerability, an attacker must be able to send an SCCP request to the targeted system. The attacker may require access to trusted network segments to send network requests to the system. In some cases, the Cisco Unified Communications Manager system may be present on separate physical or logical networks, making network access difficult and increasing the complexity of an attack.
If an exploit is successful, the attacker could cause services on the Cisco Unified Communications Manager software to fail. Users may not be able to place additional calls or access other resources, interrupting operations. An administrator may need to intervene and restart the software manually.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to cause Cisco Unified Communications Manager services to fail, resulting in the interruption of voice services provided by the affected system.
The vulnerability is due to errors in processing SCCP packets by the Cisco Unified Communications Manager software. An unauthenticated, remote attacker could exploit the vulnerability by sending a malicious network packet to the targeted system. The software may accept SCCP packets via TCP and UDP ports in the 2000 to 2443 range. Processing the malicious network messages could cause application processes to terminate, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators may consider filtering TCP ports 2000 through 2443 to allow access only to networks that require access to the Cisco Unified Communications Manager system.
Administrators are advised to implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to monitor critical systems.
The Cisco Applied Intelligence team has created the following companion document to guide administrators in identifying and mitigating attempts to exploit this vulnerability prior to applying updated software: cisco-amb-20100303-cucm
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via e-mail at email@example.com.
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