PolarDNS – A Free DNS Server For Vulnerability Research & Pentesting

DNS (Area Title System) decodes human-readable domains into IP addresses. In vulnerability analysis and pentesting, analyzing DNS can indicate the following doable assault vectors that would abet in identifying security flaws:-

• Subdomain enumeration
• Misconfigurations
• DNS-related vulnerabilities

Besides this, the DNS info could perhaps per chance even additionally present insights into the community infrastructure, which helps procedure doable targets.

Oryxlabs no longer too long previously launched a free DNS server written in Python 3.x for vulnerability analysis and pentesting, dubbed “PolarDNS.”

PolarDNS

This free DNS server, PolarDNS, permits its operators to internet fully custom DNS responses for several DNS protocol testing functions. This free server can even be former for the testing of the following issues:-

• DNS resolvers (server-aspect)
• DNS purchasers
• DNS libraries
• DNS parsers and dissectors
• Any tool handling DNS info

Over the DNS protocol layer, the operator of the PolarDNS will get fat assign an eye on because it helps the following two protocols:-

• UDP protocol
• TCP protocol

It is also succesful of manufacturing the following DNS responses:-

• Non-widespread DNS responses
• Non-compliant DNS responses
• DNS responses violating the RFC requirements
• Malformed DNS responses

On the synthetic hand, this could perhaps per chance even very smartly be worthwhile for the following functions:-

• Realistic testing
• RFC compliance
• Vulnerability analysis

Aspects & Response Modifiers

Besides this, for diverse DNS responses, the PolarDNS gives a wide resolution of built-in parts and modifiers.

Combining them creates loads of response variants, enabling testing of receivers’ handling of authentic, unparalleled, and malformed DNS responses for technical robustness.

Right here below, we own talked a pair of few of the DNS responses produced by PolarDNS that would comprise the following issues:-

• Alias (CNAME) chains and alias loops
• DNS header malformations (ID, Flags, resolution of sections)
• Injection of unsolicited info (cache poisoning)
• Injection of arbitrary bytes of arbitrary lengths
• Incomplete/empty/ NULL byte(s) responses
• Compression issues (loops, invalid pointers)
• Slowly transmitted chunked responses
• Illegal labels or arena title lengths
• An arbitrary resolution of TXT info of arbitrary dimension
• Packet dimension manipulations (TCP)

Moreover this, all these info can serve in identifying several vulnerabilities like:-

• Sloth arena assaults
• Phantom arena assaults
• Area lock-up assaults
• Cache poisoning
• Resource exhaustion
• Crashes
• DoS

With current Python and DNS protocol conception, PolarDNS facilitates straightforward implementation of:-

• Unusual concepts
• Test conditions
• Aspects
• PoCs
• Particular conditions

How to Streak it?

• First of all, enact the following list:

python polardns.py

• Now the Polardns server begins listening on localhost (127.0.0.1) by default.
• Then this could exhaust the UDP and TCP ports fifty three to address DNS queries.
• To study it’s essential to always build the following sample queries:

• In UDP mode: dig regularly.yourdomain.com @127.0.0.1
• In TCP Mode: dig regularly.yourdomain.com @127.0.0.1 +tcp

• After that, it’s essential to always be definite the response involves an A legend with the IP take care of 2.3.4.5.
• Now, if the server returns the A 2.3.4.5 legend, it indicates that Polardns is functioning because it can per chance be.

Installation

• First of all, it’s essential to always set up Python 3.10 or more moderen.
• Then you definately must set up PyYAML:

pip3 set up pyyaml

• Now, edit the configuration file polardns.yml.
• Then you definately must add your arena and nameserver IP addresses.
• That’s it, now you are done.