gavz / saddns

SADDNS: Side Channel Based DNS Cache Poisoning Attack

Introduction

SADDNS is a tool for launching the DNS cache poisoning attack. It infers the ephemeral port number and TxID by exploiting ICMP global rate limit as a side channel.

How it works

1. Scan ephemeral ports opened by the resolver.
2. Brute force TxID.

The side channel leverage the global rate limit counter as a shared resource (between the spoofed and non-spoofed IPs), which controls whether an ICMP reply should be sent or not. This gives the off-path attacker the ability to identify whether previous spoofed UDP port probing packets solicited ICMP replies or not.

The following figure shows the detail of inferring ephemeral ports.

Why spoofed IP is necessary for UDP port discovery?

• DNS software like BIND uses connect() for their northbound query sockets, which renders the port only discoverable by the NS' IP address.
• Bypass per-IP ICMP rate limit.

Additional resources

Publication

DNS Cache Poisoning Attack Reloaded: Revolutions with Side Channels

Keyu Man, Zhiyun Qian, Zhongjie Wang, Xiaofeng Zheng, Youjun Huang, Haixin Duan

In Proceedings of ACM Conference on Computer and Communications Security (CCS`20), November 9-13, 2020, Virtual Event, USA.

Website

SADDNS

How to run

The attack tool is implemented in two languages: Go and C.

The files in /saddns_go belong to Go implementation of the attack. This is the major version we maintained and contains many features to facilitate the attack. The author is Keyu Man. The detailed running instruction can be found at saddns_go/Readme.md.

The C version files are in /saddns_c and we are giving credits to our collaborator @wonderqs. The C version has a better performance and for people who are not familiar with Go. The detailed running instruction can be found at saddns_c/README.md.

Questions and issues

Please submit them by opening a new issue.