Log4Shell

TIL about the breakdown of the Log4Shell shared library.

• Date of occurence
• 24 November 2K21
• location of programmer at home with his son logging into minecraft (which failed)
• this vulnerability had existed unnoticed since 2013
• it was privately disclosed to the Apache Software Foundation { Log4j is a project}
• discloser: Chen Zhaojun of Alibaba Cloud's infosec team
• date 24 November 2021
• exploit severety MAXIMUM
• It's simple to execute
• estimation of affect ration of 50% of the internet (many hundreds of millions of devices)
• vulnerability abuses Log4j allowing requests to arbitrary LDAP and JNDI servers
• that allows attackers to
• execute arbitrary Java code on server / client
• leak sensitive data

Innerworkings

• Log4j
• open-source logging framework
• enables programmers to log data within their applications
• can include user input
• is used ubiquitously in Java programs especially enterprise software
• Originally written in 2001 by Ceki Gülcü
• part of Apache Logging Services
• project of the Apache Software Foundation

Tom Kellermann, a member of President Obama's Commission on Cyber Security

• Apache is "one of the giant supports of a bridge which facilitates the connective tissue between the worlds of applications and computer environments

Affected commercial services

• Amazon Web Services {AWS}
• Cloudflare
• iCloud {Apple infrastructure}
• Minecraft: {Java}
• Steam {multi platform gaming}
• Tencent QQ### Wiz and EY sate that the vulnerability affected 93% of enterprise cloud environments

The Log4Shell vulnerability's disclosure received strong reactions from cybersecurity experts.

Cybersecurity company Tenable stated

• exploit is "the single biggest, most critical vulnerability ever## Ars Technica
• arguably the most severe vulnerability ever

Quote
Log4j is foundational software. This 20+ year-old Java logging library quietly powers system events in applications worldwide, like user logins and calculation results. But this small piece of software had quietly become a dependency in thousands of projects across the Java ecosystem.

Opinion & reaction

• I'm blown away by the events leading to the tornadoes & typhoons that followed shortly after in the OpenSource programming World
• Fifty percent of software was affected with 93% of enterprise software sub section
• Log4Shell is a critical infrastructure level shared library
• nearly everyone using java depends on it's functional I/O

Analysis

• why do most Open Source software users only contact programmers when bugs are detected?
• why do they (almost) never get compliments when it goes well?
• programmers burn out after a while and leave projects abandoned
• when you were a kid, your mom / dad / family complimented you on good results
• programmers need the same
• otherwise they will leave the projects

Open Source programming is a thankless job

• Zero cash influx
• no thank you's
• complaints even when software has long matured to stable levels
• entitled users
• threats to be Doxxed or worse

Be nice to Open Source programmers

• If you have following contact here on the Fediverse with one say thank you
• don't expect replies (esp when hundreds to thousands of followers are indicated)
• realize you either can't code programs of that caliber or don't want to invest the time
• I am lucky to have conversational contact ont the FediVerse with critical infrastructure programmers
• I always say thank you, because I know how hard it is to write software of that magnitude
• when I review their software, I am critical, but formulate my words and sentences in a manner I would want to read them if places were switched
• I am thankful first, thus send them Universal Love and Universal Energy
• My toot history stand for these statements (on my other Fediverse accounts)

Don't be a dick!

Be nice to programmers

Give them Love

Z

#Log4Shell #TIL #programming #data #Java #exploit #ZeroDay #technology #Enterprise #networking #OpenSource #POSIX #BSD #freeBSD #ghostBSD #openBSD #Linux #win64 #mac #history #reading

Sources:

https://github.blog/open-source/inside-the-breach-that-broke-the-internet-the-untold-story-of-log4shell/

https://en.wikipedia.org/wiki/Log4Shell

#Log4Shell didn’t break #Java — it revealed it. @spoole167 shows how decades of “it still works” thinking left the Java #SupplyChain exposed & why maintenance is now a legal obligation.

See what regulators expect from Java teams: https://javapro.io/2026/01/08/the-myth-of-stability-javas-software-supply-chain-after-log4shell/

#CyberSecurity #AI

🔍 CVE-2021-44228 (Log4Shell)
Three years later, Log4Shell is still being scanned for on the internet every single day.
Why?
Legacy Java apps
Forgotten containers
Vendors who never backported fixes

👉 Breakdown & mitigation:
https://cvedatabase.com/cve/CVE-2021-44228
#CVE #Log4Shell #CyberSecurity

Who is responsible for your #Java dependencies when upstream disappears? @spoole167 traces how #Log4Shell exposed the reality of #OpenSource maintenance and why SBOMs, CRA & NIS2 changed the rules.

Learn what “responsibility” means now: https://javapro.io/2026/01/08/the-myth-of-stability-javas-software-supply-chain-after-log4shell/

#SupplyChain

Still calling unmaintained #Java libraries “stable”? After #Log4Shell, that myth collapsed. @spoole167 explains why Java’s software #SupplyChain is fragile & why regulation now forces real accountability.

Understand what changed (and why it matters): https://javapro.io/2026/01/08/the-myth-of-stability-javas-software-supply-chain-after-log4shell/

For my fellow Log4j victims celebrating 4 years #log4shell PTSD: CVE-2025-68161

"The Socket Appender in Apache Log4j Core versions 2.0-beta9 through 2.25.2 does not perform TLS hostname verification of the peer certificate, even when the verifyHostName configuration attribute or the log4j2.sslVerifyHostName system property is set to true."

https://logging.apache.org/security.html#CVE-2025-68161

(It's not that terrible. Seeing the string "log4j" just makes me twitch. :-)