Denial of service in Cisco Wide Area Application Services

1) Denial of service

EUVDB-ID: #VU7183

Risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-6721

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The weakness exists in the Cisco Wide Area Application Services (WAAS) due to incomplete input validation of TCP packets when a packet chain is fragmented. A remote attacker can send specially crafted set of TCP fragments, trigger the WAAS to drop traffic ad cause the WAASNET process to restart.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Cisco Wide Area Application Services: 6.3.1

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170621-waas

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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