#VU53029 Reachable Assertion in Unbound


Published: 2021-05-10

Vulnerability identifier: #VU53029

Vulnerability 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-2019-25041

CWE-ID: CWE-617

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Unbound
Server applications / DNS servers

Vendor: NLnet Labs

Description

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

The vulnerability exists due to a reachable assertion within the dname_pkt_copy() function when processing compressed names. A remote attacker can send specially crafted data to the DNS server, trigger an assertion failure and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Unbound: 1.9.0 rc1 - 1.9.4


External links
http://ostif.org/our-audit-of-unbound-dns-by-x41-d-sec-full-results/
http://lists.debian.org/debian-lts-announce/2021/05/msg00007.html
http://security.netapp.com/advisory/ntap-20210507-0007/


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.


Latest bulletins with this vulnerability