ASA-2018-00039 – DNSDist: Record smuggling when adding ECS or XPF

Posted on by Allele Security Intelligence in Alerts

Allele Security Alert

ASA-2018-00039

Identifier(s)

ASA-2018-00039, CVE-2018-14663

Title

Record smuggling when adding ECS or XPF

Vendor(s)

PowerDNS

Product(s)

DNSDist

Affected version(s)

PowerDNS DNSDist up to and including 1.3.2

Fixed version(s)

PowerDNS DNSDist 1.3.3

Proof of concept

Unknown

Description

An issue has been found in PowerDNS DNSDist allowing a remote attacker to craft a DNS query with trailing data such that the addition of a record by dnsdist, for example an OPT record when adding EDNS Client Subnet, might result in the trailing data being smuggled to the backend as a valid record while not seen by dnsdist. This is an issue when dnsdist is deployed as a DNS Firewall and used to filter some records that should not be received by the backend. This issue occurs only when either the ‘useClientSubnet’ or the experimental ‘addXPF’ parameters are used when declaring a new backend.

Reference(s)

PowerDNS Security Advisory for dnsdist 2018-08: Record smuggling when adding ECS or XPF
https://dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2018-08.html

PowerDNS Security Advisories for dnsdist 2018-08
https://seclists.org/oss-sec/2018/q4/141

CVE-2018-14663
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-14663

CVE-2018-14663
https://nvd.nist.gov/vuln/detail/CVE-2018-14663

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Last modified: November 8, 2018

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