Arbitrary File Write via Archive Extraction (Zip Slip)

Affecting github.com/mholt/archiver/cmd/arc package, versions >=3.0.0

Report new vulnerabilities
Do your applications use this vulnerable package? Test your applications

Overview

github.com/mholt/archiver/cmd/arc is a cross-platform, multi-format archive utility and Go library.

Affected versions of this package are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip) via the Unarchive functions.

Details

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

Remediation

There is no fixed version for github.com/mholt/archiver/cmd/arc.

References

CVSS Score

5.5
medium severity
  • Attack Vector
    Local
  • Attack Complexity
    Low
  • Privileges Required
    None
  • User Interaction
    Required
  • Scope
    Unchanged
  • Confidentiality
    None
  • Integrity
    High
  • Availability
    None
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Credit
Giulio Comi
CVE
CVE-2019-10743
CWE
CWE-29
Snyk ID
SNYK-GOLANG-GITHUBCOMMHOLTARCHIVERCMDARC-174728
Disclosed
13 May, 2019
Published
16 May, 2019