Denial of service in Cisco Unified Communications Manager

1) Improper input validation

EUVDB-ID: #VU8158

Risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-6791

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in the Trust Verification Service (TVS) due to improper handling of Transport Layer Security (TLS) traffic. A remote attacker can generate incomplete traffic streams, deny access to the TVS and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

The vulnerability is addressed in the following versions: 11.5(1.10000.6), 11.5(0.98000.806), 11.5(0.98000.566), 11.5(0.98000.260), 11.5(0.98000.208), 11.0(1.23900.5), 11.0(1.22048.1), 10.5(2.14900.16), 10.5(2.14074.1), 9.1(2.16900.2), 9.1(2.16137.1).

Vulnerable software versions

Unified Communications Manager (CallManager): 9.1\.2.10000.28\ - 11.0.1.10000.10

CPE2.3

• cpe:2.3:a:cisco_systems:unified_communications_manager_callmanager:9.1\.2.10000.28\:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:unified_communications_manager_callmanager:10.0.1.10000.24:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:unified_communications_manager_callmanager:10.5\.2.10000.5\:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ucm

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.