Vulnerability identifier: #VU53028

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-25042

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Unbound
Server applications / DNS servers

Vendor: NLnet Labs

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input within the rdata_copy() function. A remote attacker can send specially crafted data to the DNS server, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Unbound: 1.0.0 - 1.9.4

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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/

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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.