Input validation error in Unbound

1) Input validation error

EUVDB-ID: #VU32833

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2011-4528

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can cause a denial of service (daemon crash) via a crafted response. Per: http://unbound.nlnetlabs.nl/downloads/CVE-2011-4528.txt "1.4.14 is released with the patch, but 1.4.14rc1 is vulnerable.

Mitigation

Update to version 1.4.13p2.

Vulnerable software versions

Unbound: 1.4.0 - 1.4.13p1

CPE2.3

• cpe:2.3:a:unbound_net:unbound:1.4.0:*:*:*:*:*:*:*
• cpe:2.3:a:unbound_net:unbound:1.4.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:unbound_net:unbound:1.4.1:*:*:*:*:*:*:*

External links

https://lists.fedoraproject.org/pipermail/package-announce/2012-January/071525.html
https://lists.fedoraproject.org/pipermail/package-announce/2012-January/071535.html
https://osvdb.org/77909
https://secunia.com/advisories/47326
https://unbound.nlnetlabs.nl/downloads/CVE-2011-4528.txt
https://www.debian.org/security/2011/dsa-2370
https://www.kb.cert.org/vuls/id/209659

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.