The Backend Engineering Show with Hussein Nasser

Auth0 went down on April/20/2021 and this is the early report. Let us discuss. This incident affects: Auth0 US (PROD) (User Authentication, Machine to Machine Authentication, Multi-factor Authentication, Management API), Auth0 US (PREVIEW) (User Authentication, Machine to Machine Authentication, Multi-factor Authentication, Management API), and Management Dashboard (manage.auth0.com). 0:00 Update on Auth0 outage 6:00 Speculation of the outage https://auth0.com/blog/how-we-store-data-in-the-cloud-at-auth0/#Redis https://status.auth0.com/incidents/zvjzyc7912g5?u=v0zzz6jxvbv7

Let us discuss the complexity behind this trojan hack, the multi-layer approach of hiding the RAT (remote access trojan) is absolutely genius. https://en.wikipedia.org/wiki/HTML_Application https://en.wikipedia.org/wiki/Portable_Network_Graphics https://blog.malwarebytes.com/malwarebytes-news/2021/04/lazarus-apt-conceals-malicious-code-within-bmp-file-to-drop-its-rat/

Few vulnerabilities in WhatsApp for Andriod discovered that allow an attacker to send an HTML file attachment full access to the user's media, voice notes, pictures, and eventually chat messages (through TLS session resumption keys). In this video, we will discuss the scope of this attack. The vulnerabilities have been patched by facebook. Full article from CENSUS labs discussing in detail how to carry POC attack.  https://census-labs.com/news/2021/04/14/whatsapp-mitd-remote-exploitation-CVE-2021-24027/

Leaky abstractions occur when the consumer of the abstraction started asking questions about certain behavior which ends up with the need to understand the details behind the abstraction. Joel Spolsky coined this term and in this video I’d like to discuss this concept and provide few examples of my own experience towards leaky abstractions. Let us get on with the show. 6:00 Postgres Dead Tuples 7:25 MySQL Clustering 9:23 Axios HTTP Library 11:30 ORMs (N+1) 13:30 Beyond Abstractions 15:30 TCP 19:30 HTTP/2 27:00 Microservices 28:40 Index Only Scans Postgres 33:35 git 34:50 Summary Support my work on PayPal https://bit.ly/33ENps4 Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

Two weeks ago the PHP source code git server got hacked and two malicious commits were made to the source code. Since then the PHP maintainers identified the source of the hack, let us discuss

Light episode today let's have some fun with Q&A, I collected some questions on Twitter and YouTube community and I'm going to attempt to answer them here. Support my work on PayPal https://bit.ly/33ENps4 Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

In this episode, we will discuss NULLs in database systems. I’ll go through the following: What is Null? NULLs persistence Whether you store a 0 or 2 billion value in the field 32bit integer field it costs 32 bit when you store a NULL in 32 bit integer field we save 32 bit but add overheads When NULLs are naughty Semantics and inconsistent result Select count(*). Includes nulls count(column) ignores nulls T is NULL returns the null rows T is NOT NULL returns not null rows T In (NULL) returns nothing T not in NULL returns nothing Some database don’t index nulls When NULLs are useful I don’t have value , I don’t wish to provide a birthday not applicable field for certain use cases but not others fat tables (denormlization) Fat tables with many columns makes your rows longer which means fewer rows fit in your page (show pic).. NULLs help here .. that are NULL, it yields shorter rows, instead of storing a default 0 value Support my work on PayPal https://bit.ly/33ENps4 Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

The open web application security project is a recognized entity that helps developers identify critical security vulnerabilities to build secure web applications. In this video I will go through the 10 vulnerabilities and explain each one and give examples and anecdotes from real life examples. 0:00 Building Secure Backends 2:30 Injection 4:50 Broken Authentication 6:43 Sensitive Data Exposure 11:00 XML External Entities (XXE) 13:45 Broken Access Control 17:00 Security Misconfiguration 19:00 XSS 22:45 Insecure Deserialization. 24:48 Using Components with Known Vulnerabilities. 26:00 Insufficient Logging & Monitoring. Resources https://owasp.org/www-project-top-ten/ Cards 2:50 SQL Injection https://www.youtube.com/watch?v=Azo9tDUtC9s 4:20 Best practices building REST https://www.youtube.com/watch?v=6zHWU7zBep0&list=PLQnljOFTspQUybacGRk1b_p13dgI-SmcZ&index=4 8:30 TLS playlist youtube.com/playlist?list=PLQnljOFTspQW4yHuqp_Opv853-G_wAiH- 15:00 HTTP Smuggling https://www.youtube.com/watch?v=PFllH0QccCs 19:22 XSS https://www.youtube.com/watch?v=pD6C1-zSxIM 25:10 OpenSSL Crash https://youtu.be/aDPQ0_MyRnc Support my work on PayPal https://bit.ly/33ENps4 Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

Caching is the hardest problem in building software, and having the browser cache is not any different. In this video, I'll discuss Jake Archibald's article https://jakearchibald.com/2016/caching-best-practices/ 0:00 Intro 2:00 Pattern 1: Immutable content + long max-age 5:40 Pattern 2: Mutable content, always server-revalidated 8:00 max-age on mutable content is often the wrong choice 12:20 CDN and Caching Article https://jakearchibald.com/2016/caching-best-practices/ https://twitter.com/jaffathecake

Write Amplification Is a phenomenon where the actual writes that physically happen are multiples of the actual writes desired. In this episode, I'll discuss 3 types of write amplifications and their effects on performance and lifetime of storage mediums. 0:00 intro 2:00 Application write amplification 4:30 Database write amplification 9:30 SSD Disk write amplification 16:00 SSD hates BTrees 20:00 summary Resources https://en.wikipedia.org/wiki/Write_amplification https://www.cybertec-postgresql.com/en/hot-updates-in-postgresql-for-better-performance/ https://youtu.be/5Mh3o886qpg