Vulnerability identifier: #VU8666

Vulnerability risk: Medium

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-13704

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Dnsmasq
Server applications / DNS servers

Vendor: GNU

Description

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

The vulnerability exists due to boundary error in  when processing DNS queries longer than 512 bytes or EDNS0 packet size is different. A remote unauthenticated attacker can send a specially crafted DNS request to the affected service and trigger the application crash.

Successful exploitation of this vulnerability may allow an attacker to perform a denial of service (DoS) attack.

Mitigation
Update to version 2.78.

Vulnerable software versions

Dnsmasq: 2.77

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External links
http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2017q4/011771.html
http://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html

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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.