#VU45821 Reachable Assertion in ISC BIND


Published: 2020-08-20

Vulnerability identifier: #VU45821

Vulnerability risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-8620

CWE-ID: CWE-617

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
ISC BIND
Server applications / DNS servers

Vendor: ISC

Description

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

The vulnerability exists due to a reachable assertion in tcpdns.c when processing large TCP payloads. An attacker who can establish a TCP connection with the server and send data on that connection can exploit this to trigger the assertion failure, causing the server to exit.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

ISC BIND: 9.15.0 - 9.17.3


External links
http://kb.isc.org/docs/cve-2020-8620


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. However, proof of concept for this vulnerability is available.


Latest bulletins with this vulnerability