Denial of service in Cisco IOS and IOS XE Software

1) Improper Interaction Between Multiple Correctly-Behaving Entities

EUVDB-ID: #VU56873

Risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-34699

CWE-ID: CWE-435 - Improper Interaction Between Multiple Correctly-Behaving Entities

Exploit availability: No

Description

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

The vulnerability exists due to an improper interaction between the web UI and the CLI parser. A remote authenticated attacker can request a particular CLI command to be run through the web UI and cause a denial of service condition on the target system. 

Mitigation

Install update from vendor's website.

Vulnerable software versions

Cisco IOS: 16.12.3 - 17.3.2

Cisco IOS XE: 16.12.3 - 17.3.2

CPE2.3

• cpe:2.3:o:cisco_systems:cisco_ios:16.12.3:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios:17.3.2:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xe:16.12.3:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xe:17.3.2:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-trustsec-dos-7fuXDR2

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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