Denial of service in Cisco Small Business Smart and Managed Switches

1) Input validation error

EUVDB-ID: #VU45896

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-3496

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing IPv6 packets. A remote attacker can pass specially crafted IPv6 traffic to the device and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco 250 Series Smart Switches: 2.5.0.90 - 2.5.5.47

Cisco 350 Series Managed Switches: 2.5.0.90 - 2.5.5.47

Cisco 350X Series Stackable Managed Switches: 2.5.0.92 - 2.5.5.47

Cisco 550X Series Stackable Managed Switches: 2.5.0.90 - 2.5.5.47

Cisco Small Business 200 Series Smart Switches: 1.3.7.18 - 2.5.5.47

Cisco Small Business 300 Series Managed Switches: 1.3.7.18 - 2.5.5.47

Cisco Small Business 500 Series Stackable Managed Switches: 1.3.7.18 - 2.5.5.47

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sbss-ipv6-dos-tsgqbffW
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvt45826

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 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.