Sealing Wafter – Defend Against OS Fingerprinting for OpenBSD


One way to defend against OS fingerprinting from tools such as nmap, queso, p0f, xprobe etc is to change the metrics that they base their analysis on.

One way to do this with OpenBSD is to use Sealing Wafter.

Goals of Sealing Wafter:
1. To reduce OS detection based on well known fingerprints network stack behavior.
2. To have the ability to load custom rules into the stack.
3. To unload, modify, reload the kernel module with on the fly rules. (great feature at packet parties)
4. To learn how the magic of tcpip stacks work.

What Sealing Wafter currently provides:
1. Hide from Nmap Syn/Xmas/Null scans, as well as the specific fingerprinting packets.
2. Ability to see what your stack is receiving without the need to drop your network device into promisc mode.
3. Complete control over rules that you can load on the fly todeal with specific incoming packets.
4. Initial support for several OS passive detection has been added for SYNs.

Weaknesses in current Sealing Wafter:
1. Full connection scans. e.g. nmap -sT will still find open ports. this is because I have yet to find anything that seperates a real tcp connection vs an nmap full connection. (most likely isn’t one.)
2. Can be very verbose when under heavy load. I have run this on my heaviest web servers, and have not noticed any major overhead.

Download the c code for the LKM here: Sealing Wafter

Posted in: Countermeasures, Networking Hacking, UNIX Hacking

, ,


Latest Posts:


SecLists - Usernames, passwords, URLs, sensitive data patterns, fuzzing payloads, web shells SecLists – Usernames, passwords, URLs, sensitive data patterns, fuzzing payloads, web shells
SecLists is the security tester's companion. It's a collection of multiple types of lists used during security assessments, collected in one place.
DeepSound - Audio Steganography Tool DeepSound – Audio Steganography Tool
DeepSound is an audio steganography tool and audio converter that hides secret data into audio files, the application also enables you to extract from files.
2019 High Severity Vulnerabilities What are the MOST Critical Web Vulnerabilities in 2019?
So what is wild on the web this year? Need to know about the most critical web vulnerabilities in 2019 to protect your organization?
GoBuster - Directory/File & DNS Busting Tool in Go GoBuster – Directory/File & DNS Busting Tool in Go
GoBuster is a tool used to brute-force URIs (directories and files) in web sites and DNS subdomains (inc. wildcards) - a directory/file & DNS busting tool.
BDFProxy - Patch Binaries via MITM - BackdoorFactory + mitmProxy BDFProxy – Patch Binaries via MiTM – BackdoorFactory + mitmproxy
BDFProxy allows you to patch binaries via MiTM with The Backdoor Factory combined with mitmproxy enabling on the fly patching of binary downloads
Domained - Multi Tool Subdomain Enumeration Domained – Multi Tool Subdomain Enumeration
Domained is a multi tool subdomain enumeration tool that uses several subdomain enumeration tools and wordlists to create a unique list of subdomains.


Comments are closed.