Arbitrary File Write via Archive Extraction (Zip Slip) Affecting org.apache.hadoop:hadoop-common package, versions [,2.10.2) [3.0.0-alpha1,3.2.3) [3.3.0,3.3.3-RC0)

org.apache.hadoop:hadoop-common is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models.

Affected versions of this package are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip) in FileUtil where unpackEntries during TAR extraction follows symbolic links which allows writing outside the expected base directory on Windows. This is because getCanonicalPath doesn't resolve symbolic links on Windows.

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

• Apache Thread
• GitHub Commit
• GitHub Commit
• GitHub Fix Commit v3.2.3
• GitHub PR
• Hadoop Jira
• Vulnerable Code