The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Security’ Category

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Kristian Köhntopp on Twitter: “Modaler Filter für Veloziraptoren… ” (0 factor authentication)

Posted by jpluimers on 2021/10/08

[WayBack] Kristian Köhntopp on Twitter: “Modaler Filter für Veloziraptoren… “

–jeroen

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Posted in Authentication, Power User, Security | Leave a Comment »

Teams, hats and colours

Posted by jpluimers on 2021/10/06

I learned a few new things a while ago, but still have a hard time to get the association between colours and meanings right.

Colours:

  • white: friendly / sanctioned / by permission
  • black: enemy / unsanctioned
  • red: attacks by permission
  • blue: defends by permission

Based on these tweets and links:

 

–jeroen

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Posted in Development, LifeHacker, Power User, Security, Software Development | Leave a Comment »

Solved: ‘Answering Yes to “You have an older version of PackageManagement known to cause issues with the PowerShell extension. Would you like to update PackageManagement (You will need to restart the PowerShell extension after)?” hung my Visual Studio Code.…’

Posted by jpluimers on 2021/10/04

From a while back: [Archive.is] Jeroen Wiert Pluimers on Twitter: ‘Answering Yes to “You have an older version of PackageManagement known to cause issues with the PowerShell extension. Would you like to update PackageManagement (You will need to restart the PowerShell extension after)?” hung my Visual Studio Code.… ‘

After clicking “Yes”, the the only thing visible was this notification that had an ever running “progress bar”:

Notifications - Powershell - Source: Powershell (Extension)

Notifications – Powershell – Source: Powershell (Extension)

The first part of the solution was relatively simple: restart Visual Studio code, then the original notification showed, and after clicking “Yes”, the “Panel” (you can toggle it with Ctrl+J) showed the “Terminal” output (yes, I was working on [Wayback/Archive.is] PowerShell script for sending Wake-on-LAN magic packets to given machine hardware MAC address, more about that later):

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Posted in .NET, Communications Development, Development, Encryption, HTTP, HTTPS/TLS security, Internet protocol suite, Power User, Security, Software Development, TCP, Visual Studio and tools, vscode Visual Studio Code, Windows, Windows 10 | Leave a Comment »

One of the Let’s Encrypt’s Root Certificates expired today (and their corresponding intermediate yesterday); how is your infrastructure doing?

Posted by jpluimers on 2021/09/30

Last weekend I published 5 days before the Let’s Encrypt’s Root Certificate is expiring!

It basically was a post trying to amplify the [Wayback/Archive.is] Let’s Encrypt’s Root Certificate is expiring! message by [Wayback] Scott Helme .

Yesterday and today, he is maintaining a Twitter thread on things that have broken.

Quite a few things have, including some versions of curl, on which a lot of infrastructure relies (the certificate for it got fixed later on 20120930), see:

Two important starting points in his thread:

  1. [Archive.is] Scott Helme on Twitter: “🚨🚨🚨 5 minutes until the Let’s Encrypt R3 intermediate expires 🚨🚨🚨 29 September 2021 19:21:40 UTC”
  2. [Archive.is] Scott Helme on Twitter: “🚨🚨🚨 30 minute warning 🚨🚨🚨 IdentTrust DST Root CA X3 Expires: Sep 30 14:01:15 2021 UTC… “

If you want to check from one of your own clients, try [Archive.is] Scott Helme on Twitter: “I’ve created a test site to help identify issues with clients. If you can connect to https://t.co/bXHsnlRk8D then your client can handle being served the expired R3 Intermediate in the server chain!… “

[Wayback/Archive.is] https://expired-r3-test.scotthelme.co.uk/

Note that neither SSLabs, nor Cencys, nor CertCheckkerApp do show the expired certificate, only the new one:

Yes, I know the pluimers.com web server is rated B from a TLS perspective. Will be working on it, but I’m still recovering from rectum cancer treatments, and have an almost 1.5 year backlog to get through.

–jeroen

Posted in Communications Development, Development, Encryption, HTTP, https, HTTPS/TLS security, Internet protocol suite, Let's Encrypt (letsencrypt/certbot), Power User, Security, Software Development, TCP, TLS, Uncategorized, Web Development | Leave a Comment »

5 days before the Let’s Encrypt’s Root Certificate is expiring!

Posted by jpluimers on 2021/09/24

Only 5 days left to take a close look at both your web-clients (including back-end clients!) and servers to prevent potential Let’s Encrypt mayhem.

Last week, [Wayback] Scott Helme published about [Wayback/Archive.is] Let’s Encrypt’s Root Certificate is expiring!

Let’s Encrypt has done loads of work over the past lustrum to prevent trouble like cross-signing, issuing the successor certificates, and more.

The problem is that people like you and me have refrained from keeping their clients and servers up-to-date, so some security issues will occur. Hopefully they are limited to non-functioning communication and not leaking of data.

It is about this DST Root CA X3 certificate, used by the vast majority of Let’s Encrypt certificates, [Wayback/Archive.is] Certificate Checker: CN=DST Root CA X3, O=Digital Signature Trust Co.:

DST Root CA X3
Certificate Trusted anchor certificate
Subject DN CN=DST Root CA X3, O=Digital Signature Trust Co.
Issuer DN CN=DST Root CA X3, O=Digital Signature Trust Co.
Serial Number 44AFB080D6A327BA893039862EF8406B
Valid  to  Key RSAPublicKey (2048 bit)
SHA1 Hash DAC9024F54D8F6DF94935FB1732638CA6AD77C13 MD5 Hash 410352DC0FF7501B16F0028EBA6F45C5
SKI C4A7B1A47B2C71FADBE14B9075FFC41560858910 AKI

Quoting Scott, these clients likely will fail, so need attention:

  • OpenSSL <= 1.0.2
  • Windows < XP SP3
  • macOS < 10.12.1
  • iOS < 10 (iPhone 5 is the lowest model that can get to iOS 10)
  • Android < 7.1.1 (but >= 2.3.6 will work if served ISRG Root X1 cross-sign)
  • Mozilla Firefox < 50
  • Ubuntu < 16.04
  • Debian < 8
  • Java 8 < 8u141
  • Java 7 < 7u151
  • NSS < 3.26
  • Amazon FireOS (Silk Browser)

On the server side, you can help Android devices by using a Let’s Encrypt certificate that is cross-signed with the ISRG Root X1 certificate [Wayback/Archive.is] Certificate Checker: CN=ISRG Root X1, O=Internet Security Research Group, C=US:

ISRG Root X1
Certificate
Subject DN CN=ISRG Root X1, O=Internet Security Research Group, C=US
Issuer DN CN=DST Root CA X3, O=Digital Signature Trust Co.
Serial Number 4001772137D4E942B8EE76AA3C640AB7
Valid  to  Key RSAPublicKey (4096 bit)
SHA1 Hash 933C6DDEE95C9C41A40F9F50493D82BE03AD87BF MD5 Hash C1E1FF07F9F688498274D1A18053EABF
SKI 79B459E67BB6E5E40173800888C81A58F6E99B6E AKI C4A7B1A47B2C71FADBE14B9075FFC41560858910

Via [Archive.is] Scott Helme on Twitter: “There are only 10 days left until the Let’s Encrypt root certificate expires and there are still questions over what the impact will be! Full details here: …” which links to the above article showing a nice graph of the current Let’s Encrtypt root certificate setup:

–jeroen

Posted in Communications Development, Development, Encryption, https, HTTPS/TLS security, Internet protocol suite, Let's Encrypt (letsencrypt/certbot), Power User, Security, Software Development, TCP, TLS, Web Development | Leave a Comment »

Laat Je Niet Hack Maken: een goed wachtwoord kiezen of maken

Posted by jpluimers on 2021/09/13

[WayBack] Laat Je Niet Hack Maken: een goed wachtwoord

Laat Je Niet Hack Maken legt op een begrijpelijke manier uit hoe je jezelf beschermt tegen hackers.

–jeroen

via:

https://twitter.com/danielverlaan/status/1174262886472048640

Posted in LifeHacker, Power User, Security | Leave a Comment »

Hardening your network from locally logged on users

Posted by jpluimers on 2021/09/10

SwiftOnSecurity is a great account to follow.

One tweet was the base of my post [WayBack] On Windows, having an empty password can improve security.

Another tweet the base of this one.

Doug is great!

Swift has some great github resources too:

–jeroen

Posted in Power User, Security, Windows | Leave a Comment »

For my link archive: DNS over https

Posted by jpluimers on 2021/09/02

DNS over HTTPS

For my link archive:

JSON DNS output

Some DNS over HTTSP providers support dns-json, which Cloudflare delivers non-pretty printed.

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Posted in Cloud, Cloudflare, Communications Development, Development, DNS, Encryption, HTTP, https, HTTPS/TLS security, Infrastructure, Internet, Internet protocol suite, Power User, Security, Software Development, TCP, TLS | Leave a Comment »

Ryan O’Horo on Twitter : “Computerphile with a clear and complete explanation of how the block cipher AES works and how it’s different from older ciphers. Background info… “

Posted by jpluimers on 2021/09/01

From a while back, but still relevant: [WayBack] Ryan O’Horo sur Twitter : “Computerphile with a clear and complete explanation of how the block cipher AES works and how it’s different from older ciphers. Background https://t.co/WyvYpM5JJN SP Networks https://t.co/MGILCxkqUR AES Cipher https://t.co/ReHpnCBTvI… https://t.co/VbZomPrOow”

Videos below the fold

–jeroen

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Posted in Development, Encryption, Hashing, Power User, Security, Software Development | Leave a Comment »

Some links related to Apple’s NeuralHash algorithm, as it was reverse engineered and collisions can be generated so abuse with pictures matching sensitive hashes can be performed

Posted by jpluimers on 2021/08/24

Last week, I wrote [Archive.is] Jeroen Wiert Pluimers on Twitter: “Apple’s NeuralHash algorithm for automagically reporting sensitive images from iOS devices has not only been reverse engineered, but also collisions can now be generated. Now just wait for abuse of innocent pictures matching sensitive hashes. … “

Below, for my link archive, some relevant links on this:

–jeroen

Posted in AI and ML; Artificial Intelligence & Machine Learning, Development, Hashing, Power User, Security, Software Development | Leave a Comment »

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