Arbitrary File Write via Archive Extraction (Zip Slip) Affecting cn.hutool:hutool-core package, versions [,4.1.12)

cn.hutool:hutool-core is a set of tools for java.

Affected versions of the package are vulnerable to Arbitrary File Write via Archive Extraction (AKA "Zip Slip").

It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

+2018-04-15 22:04:29 ..... 19 19 good.txt

+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys

• https://github.com/looly/hutool/commit/8d7d0b7fb5ea4f7447b40131bffc1ec506a6528e
• https://github.com/looly/hutool/commit/9f8a801c7b98b75ee681c0988e1a58bcfdc21756
• https://github.com/looly/hutool/commit/fed1a1f747a9308e2f65f8dbbff05ce62478ecc0
• https://github.com/looly/hutool/issues/162