Impact

Logistics Pipes is a modification (a.k.a. mod) for the computer game Minecraft Java Edition. The mod used Java's ObjectInputStream#readObject on untrusted data coming from clients or servers over the network resulting in possible remote code execution when sending specifically crafted network packets after connecting. The affected versions were released between 2013 and 2016 and the issue (back then unknown) was fixed in 2016 by a refactoring of the network IO code.
The issue is present in all Logistics Pipes versions ranged from (0.7.0.91, 0.10.0.71], which were downloaded from different platforms summing up to multi-million downloads. On GitHub the issue was introduced by commit 527c4f4 and fixed in commit 39a90b8.

Patches

For Minecraft version 1.7.10 the issue was fixed in build 0.10.0.71. Everybody on Minecraft 1.7.10 should check their version number of Logistics Pipes in their modlist and update, if the version number is smaller than 0.10.0.71. Newer versions can be obtained here: https://ci.rs485.network/view/Logistics%20Pipes%20Archive/job/LogisticsPipes-0.10-mc17-bc7/
Any newer supported Minecraft version (like 1.12.2) never had a Logistics Pipes version with vulnerable code.

Workarounds

The best available workaround for vulnerable versions is to play in singleplayer only or update to newer Minecraft versions and modpacks.
The project https://github.com/dogboy21/serializationisbad provides a mod preventing remote code execution via deserialization via ObjectInputStream#readObject.

References

• Java 8 ObjectInputStream documentation: https://docs.oracle.com/javase/8/docs/api/java/io/ObjectInputStream.html
• Java 20 ObjectInputStream documentation (including a warning about deserializing untrusted data): https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/io/ObjectInputStream.html
• Recently published summary of Minecraft mods that are believed to be vulnerable: https://github.com/dogboy21/serializationisbad
• Blogpost explaining the ObjectInputStream#readObject vulnerability: https://snyk.io/blog/serialization-and-deserialization-in-java/
• Similar issue in SuperMartijn642's Config Lib: GHSA-f4r5-w453-2jx6