#VU32833 Input validation error in Unbound - CVE-2011-4528

Vulnerability identifier: #VU32833

Vulnerability 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

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Unbound
Server applications / DNS servers

Vendor: NLnet Labs

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 rc1 - 1.4.13p1

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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

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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.