Denial of service in F5 BIG-IP DNS virtual server

1) Resource management error

EUVDB-ID: #VU49071

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-27721

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

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

The vulnerability exists due to improper management of internal resources within the BIG-IP DNS system.

This can occur under the following conditions:

• You configure connection rate limiting by either source or destination address for a BIG-IP LTM virtual server.
• The configured connection rate limit is exceeded on the BIG-IP LTM virtual server (or Pool Member or Node), and the status of the virtual server on the Configuration utility becomes yellow.
  

A remote attacker can send specially crafted data to the service and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

BIG-IP DNS: 11.6.1 - 16.0.0

BIG-IP GTM: 11.6.1 HF1 - 16.0.0

CPE2.3

• cpe:2.3:h:f5_networks:big-ip_dns:11.6.1:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip_dns:11.6.2:HF1:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip_dns:11.6.2:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip_gtm:11.6.1 HF1:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip_gtm:11.6.1:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip_gtm:11.6.2 HF1:*:*:*:*:*:*:*

External links

http://support.f5.com/csp/article/K52035247

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.