Denial of service in Cisco Small Business Managed Switches

1) Denial of service

EUVDB-ID: #VU8561

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-6720

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The weakness exists in the Secure Shell (SSH) subsystem of Cisco Small Business Managed Switches due to improper processing of SSH connections. A remote attacker can log in to an affected switch via SSH and send a malicious SSH message to cause the switch to reload.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Update Cisco Small Business 300 Series Managed Switches, Cisco Small Business 500 Series Stackable Managed Switches and Cisco ESW2 Series Advanced Switches to version 1.4.8.06.
Update Cisco 350 Series Managed Switches, Cisco 350X Series Stackable Managed Switches and Cisco 550X Series Stackable Managed Switches to version 2.3.0.130.

Vulnerable software versions

Cisco 550X Series Stackable Managed Switches: All versions

Cisco 350X Series Stackable Managed Switches: All versions

Cisco 350 Series Managed Switches: All versions

Cisco ESW2 Series Advanced Switches: All versions

Cisco Small Business 500 Series Stackable Managed Switches: All versions

Cisco Small Business 300 Series Managed Switches: All versions

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170920-sbms

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

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

Is there known malware, which exploits this vulnerability?

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