Apache Log4j 2
ysoserial
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Apache Log4j 2 | ysoserial | |
---|---|---|
108 | 13 | |
3,268 | 7,291 | |
0.9% | - | |
9.9 | 0.0 | |
about 14 hours ago | 26 days ago | |
Java | Java | |
Apache License 2.0 | MIT License |
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Apache Log4j 2
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Hackers exploited Windows 0-day for 6 months after Microsoft knew of it
I don't think that's a good example. While Apache devs are volunteers and Microsoft devs are employees, they were criticized for their slow response time and seeming lack of urgency until it was far too late.
https://github.com/apache/logging-log4j2/pull/608#issuecomme...
- Create an alternative async logger implementation using JCTools
- Log4j requesting feedback on which modules/features to drop
- The Unsung Heroes of Open Source: The Dedicated Maintainers Behind Lesser-Known Projects
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Studying Log4Shell
The official website. The vulnerability was introduced in 2.0-beta7 which was released in 2013.
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The Dedicated Maintainers Behind Lesser-Known Open Source Projects
However, there are many open source projects that are widely used but not well-known, including cURL, ImageMagick, MyCLI, Homebrew, Apache Log4j, and OpenSSL. This article will take a closer look at these unsung heroes of the open source world. I do not want to give them a business model or financial advice in this article. This largely depends on the author's personal experience and values. I just want to raise more awareness about these open source projects.
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Apache POI Setup Logging Error
What you need is log4j-core, what you downloaded is some kind of connector between log4j and JUL. Tbh I don't know what JUL is, but that's not important. You can get log4j-core on from the official website - https://logging.apache.org/log4j/2.x/ or in maven repo. In case you're not using maven, I highly, highly recommend you using it for managing your dependencies.
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Log4Shell Still Has Sting in the Tail
> When it was first revealed in early December 2021, the Log4Shell bug was described as one of the most severe security vulnerabilities ever.
> The Apache Software Foundation, which maintains the open-source tool, quickly released a patch...
Apache horribly mismanaged this and did not release a patch until it was already widely known and being exploited in the wild. They also messed up and had to release several subsequent patches to actually fix the vulnerability.
Remember: this vulnerability was disclosed to them in November.
https://github.com/apache/logging-log4j2/pull/608#issuecomme...
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The US Cybersecurity and Infrastructure Agency open-sourced a new tool named Scuba
Think back to the Log4J event, were you affected? (https://github.com/apache/logging-log4j2)
- In One Minute : log4j2
ysoserial
- anybody got ysoserial to work in kali 2022 running java v17?
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Java deserialization payloads in log4j (Unified starting point)
So I've finished the unified box in stage 2 of the starting point and have tons of questions about the box. In the box they use veracode-research/rogue-jndi to exploit the log4j vulnerability. But when I test it with deserialize payload generated by frohoff/ysoserial it's not running. I've try to look at the java log in the challenge container but can't find anything that java complain or error out. Is it because the ysoserial payload too complex that it running but fail at some point and don't throw error or maybe the author just hard code so that only the payload from rogue-jndi work? can it's because of the java version/framework/library/weirdness? Do I need to test both kind of payload if I want to exploit log4j in the future or just stick with pimps/JNDI-Expoit-Kit or cckuailong/JNDI-Injection_Exploit-Plus (my senior recommendation when exploiting log4j).
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An Unsafe Deserialization Vulnerability and Types of Deserialization
GitHub - Ysoserial
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Great Time at JavaZone 2022
A gadget lets you run load a different class upon serialization. This will fail later when we downcast but during the read process we can load a different class where we can do arbitrary code execution. HashMap is a class that overrides the readObject and can be used as part of an exploit chain. ysoserial helps us create a chain of serialization to produce an exploit based on known serialization weaknesses. You can run this project and generate payload ser files that you can pass to exploit potential vulnerabilities.
- PoC tool for creating payloads that exploit unsafe Java object deserialization
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Is Java as safe as we believe?
gadget chain attack: is a type of exploit where an attacker uses a series of "gadgets" — small pieces of code that perform a specific function — to execute a larger, more complex attack. By chaining together these gadgets, an attacker can gain control of a target system or perform other malicious actions. You can use ysoserial to create a serialize payload java -jar path/to/ysoserial.jar CommonsCollections4 'whoami'
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Is Haskell a Good Choice for Software Security?
> A similar issue has occurred with Java (and other languages, see https://frohoff.github.io/appseccali-marshalling-pickles/). Java provided a suberbly user-friendly way of serializing any object to disk and recovering it back in its original form. The only unfortunate problem was that there was no way to say which object you are expecting! This allows attackers to send you objects that, upon deserialization in your program, become nasties that wreak havoc and steal data.
Not correct. You can certainly inspect before instantiation:
https://docs.oracle.com/javase/7/docs/platform/serialization...
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Log4j 2.15.0 – Previously suggested mitigations may not be enough
Mmh, I don't think so. Beside logging most other libraries will already sanitize user input since it is a more commonly known attack vector for those kind of libraries. I would compare the vulnerability to https://github.com/frohoff/ysoserial.
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Analysis of the 2nd Log4j CVE published earlier (CVE-2021-45046 / Log4Shell2)
Exactly. eg. https://github.com/frohoff/ysoserial#usage
Note the classes aren't at fault or doing anything wrong (even though you could imagine other mitigations they could use), they are just conveniently there to use if you have a vulnerability that lets you de-serialize untrusted data.
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RCE 0-day exploit found in log4j, a popular Java logging package
This has been known for a zillion years and has caused a zillion CBEs, so at this point there are off-the-shelf tools like ysoserial that take your payload and wrap it into an object that kabooms when deserialized, with like 20 different choices of methods depending on what dangerous objects are available on the target's classpath for deserialization.
What are some alternatives?
Logback - The reliable, generic, fast and flexible logging framework for Java.
jsoniter - jsoniter (json-iterator) is fast and flexible JSON parser available in Java and Go
reload4j - reload4j is a drop-in replacement for log4j 1.2.17
log4shell-ldap - A tool for checking log4shell vulnerability mitigations
tinylog - tinylog is a lightweight logging framework for Java, Kotlin, Scala, and Android
log4shell-tools - Tool that runs a test to check whether one of your applications is affected by the recent vulnerabilities in log4j: CVE-2021-44228 and CVE-2021-45046
Logstash - Logstash - transport and process your logs, events, or other data
PHP Serializer - A Java library for serializing objects as PHP serialization format.
SLF4J - Simple Logging Facade for Java
Arthas - Alibaba Java Diagnostic Tool Arthas/Alibaba Java诊断利器Arthas
kibana - Your window into the Elastic Stack
fastjson - FASTJSON 2.0.x has been released, faster and more secure, recommend you upgrade.