Denial of service in ISC BIND

1) Assertion failure

EUVDB-ID: #VU10785

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-2018-5734

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 assertion failure in badcache.c file when processing a DNS request that does not contain all of the expected information. A remote attacker can send a malformed packet to vulnerable version of BIND, trigger the application to select a SERVFAIL rcode instead of a FORMERR rcode and perform a denial of service attack.

Successful exploitation of the vulnerability allows an attacker to trigger denial of service conditions on servers configured to allow recursion with enabled SERVFAIL cache.

Mitigation

Install the latest version from vendor's website.

Vulnerable software versions

ISC BIND: 9.10.5-S1 - 9.10.6-S2

External links

http://kb.isc.org/article/AA-01562/74/CVE-2018-5734%3A-A-malformed-request-can-trigger-an-assertion...

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 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.