DNS Rebinding and the Fallacy of "Walled Gardens"

Attacking Private Networks from the Internet with DNS Rebinding

The well-written research article above by Brannon Dorsey is a must-read for any developer of home-integrated devices, and perhaps, all developers, even those who develop products that run within highly secure networks that, via an authenticated user- (as was done with Stuxnet)- can inadvertently intercept and execute malicious code.

Don't let script kiddies mess with your code via DNS

Essentially Mr. Dorsey discovered that smart home gadgets that are supposed to operate securely in private networks can be exploited from the outside by simply embedding scripts containing network hi-jack exploits in links that can make requests back to the client browser that appear- via dynamic IP-to-same-origin-hostname switching* (ie. "DNS Spoofing") done through a malicious DNS server -to be from a trusted, same-origin source.

ie.

Malicious hostname: exploit.net
Malicious ip address: 59.33.12.9

Victim recent request hostname: somebank.com
Victim recent request ip address: 122.76.21.19

<<Very brief DNS Hijack via a malicious DNS server>>

Malicious hostname: exploit.net
Malicious ip address as far as victim browser client is aware: 122.76.21.19

......See the problem?

He goes on to explain how entire protocols like UPnP "are built around the idea that devices on the same network can trust each other".

Remember: what appears to the browser client to be a "same-origin" request is not always actually a same-origin request. Make sure that you change the default credentials on your network router(s) and as the article above insists:

"We need developers to write software that treats local private networks as if they were hostile public networks. The idea that the local network is a safe haven is a fallacy. If we continue to believe it people are going to get hurt."

Good to remember: protocol://host:port/path?query

*DNS cache poisoning, also known as DNS spoofing, is a type of attack that exploits vulnerabilities in the domain name system (DNS) to divert Internet traffic away from legitimate servers and towards fake ones.

Visualize Hashing and Salt as Part of Password Encryption Process

The image below is a simplified and easy-to-understand illustration of how hashing and salting work. The main takeaway from this post- multiple users can have the same password, but will all have different salt values, thus making their hash result value different, and when you authenticate, you authenticate by the hash result value of your passwords, which is virtually always going to be unique for each user record:

Simple, no?

Even in the case of 2 users having the same hash result, the usernames will/should not be the same, so you still have distinct accounts, because UserID is also checked in the authentication process.

Companies increasingly (and for good data privacy reasons) do not even store the clear text textbox value you enter when you sign up for and then log into Fb, Google, Amazon, etc- they check your entered password's hash result against the hash result they have for your user/account record either from when you registered or last changed your password.

Good answer to the question you may come across, "what is the difference between salt and an IV (initialization vector)?" (TL;DR: not all IV's are salt, but salt is a kind of IV): https://security.stackexchange.com/questions/6058/is-real-salt-the-same-as-initialization-vectors

Reference: https://www.slideshare.net/rahulrajatsingh/password-hashing-28725754

Quality Control

You should know at least the surface topics surrounding TQM (Total Quality Management) because nearly all modern businesses practice TQM strategies and tactics to reduce costs and ensure top quality.

But first, check out this old video clip of America discovering something that ironically, an American (W. Edwards Deming) exported to Japan with great success years before:

1980 NBC News Report: "If Japan Can, Why Can't We?"

So big-Q "Quality" became a bit hit and has been embedded in process management throughout the globe ever since.

I think he has a point here.

Here are some Quality buzz words that surely you've heard before:

ASQ - American Society for Quality

"Black Belt" - Ooo. Ahh. It does mean something. It means a person has passed a series of very difficult exams on statistics and statistical process control for quality based on the quantitative technics and measures originated in Japan by W. Edwards Deming.

ISO 9001 - the International standard of a Quality Management System that is used to certify that business processes follow standard process and product guidelines.

Kaizen - a long-term approach to work that systematically seeks to achieve small, incremental changes in processes in order to improve efficiency and quality.

Kanban -  a visual system for managing work as it moves through a process.

Lean - a synonym for continuous improvement through balanced efficiency gains.

Example of statistical process control using UCL and LCL boundaries and a process (Fall Rate) improving.

LCL*  - Lower Control Limit - The negative value beyond which a process is statistically unstable.

MAIC - Measure, Analyze, Improve, Control.

Service Level Agreements (SLA) - A contract between a service provider and end user that defines the expected level of service to the end user.

UCL* - Upper Control Limit - The positive value beyond which a process is statistically unstable.

Uptime - Uptime is a measure of the time a service is working and available and opposite of Downtime.

Six Sigma - a statistical approach to process improvement and quality control; sometimes defined as +/-3 three deviations for the mean ("6"), sometimes as +/-6 deviations from mean.

The table above gives you an idea of realistic process improvement numbers (66,800 == a lot of defective items)

History and W. Edwards Deming
Quality Management is a permanent organizational approach to continuous process improvement. It was successfully applied by W. Edwards Deming in post-WWII Japan. Deming's work began in August 1950 at the Hakone Convention Center in Tokyo, when Deming delivered a speech on what he called "Statistical Product Quality Administration".

He is credited with helping hasten Japanese recovery after the war and then later helping American companies embrace TQM and realize significant efficiency and quality gains.

Deming's 14 Points for Total Quality Management

*Measures such as standard deviation and other distribution-based statistics determine the LCL and UCL for a process (any process- temperature of a factory floor, time to assemble a component, download/upload speed, defects per million, etc.).

References:

http://asq.org/learn-about-quality/total-quality-management/overview/deming-points.html

https://www.quora.com/How-did-W-Edwards-Deming-influence-Japanese-manufacturing