SCALE - Automatically Finding RFC Compliance Bugs in DNS Nameservers

Explore a 16-minute conference talk from NSDI '22 that introduces SCALE (Small-scope Constraint-driven Automated Logical Execution), a groundbreaking approach for automatically detecting RFC compliance bugs in DNS nameserver implementations. Learn about Ferret, a tool developed based on SCALE, which generates zone files and queries to test DNS resolution behaviors. Discover how this innovative method uncovered 30 new unique bugs across 8 open-source DNS implementations, including popular ones like Bind, PowerDNS, Knot, and Nsd. Gain insights into the complexities of DNS, the importance of RFC compliance, and the critical vulnerability found in Bind that could be exploited to remotely crash DNS resolvers and nameservers. Understand the limitations of standard automated testers and how SCALE overcomes these challenges to improve DNS software reliability and security.

Intro
Many DNS Implementations
DNS Software needs to be absolutely
How the Domain Name System Wo
DNS is way more complex than people
BIND Crash Remote Exploitation
BIND Crash Disclosure
Standard Automated Testers are insufficie
Our Approach
FERRET: Tool based on SCALE for DN
Test Generation Module
Challenge - Generating Valid Zone
Exhaustive Model Coverage with Test Ge
Bugs Found and Confirmed in Ope source DNS Implementations
Summary