Denial of service in ISC Bind

1) Reachable Assertion

EUVDB-ID: #VU29184

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-8618

CWE-ID: CWE-617 - Reachable Assertion

Exploit availability: No

Description

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

The vulnerability exists due to a reachable assertion in rdataset.c when processing large responses during zone transfers. A remote attacker with ability to send zone data to a server via zone transfer can exploit this to intentionally trigger memory corruption and assertion failure with a specially constructed zone, denying service to clients.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ISC BIND: 9.11.0 - 9.17.1

External links

http://kb.isc.org/docs/cve-2020-8618

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 application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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