Arbitrary File Write via Archive Extraction (Zip Slip) Affecting org.jenkins-ci.main:jenkins-core package, versions [,2.120)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.07% (31st percentile)

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  • Snyk ID SNYK-JAVA-ORGJENKINSCIMAIN-31683
  • published 6 Jun 2018
  • disclosed 19 Sep 2015
  • credit Snyk Security research Team

How to fix?

Upgrade org.jenkins-ci.main:jenkins-core to version 2.120 or higher.

Overview

org.jenkins-ci.main:jenkins-core is an open-source automation server.

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

CVSS Scores

version 3.1
Expand this section

Snyk

Recommended
5.4 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    Required
  • Scope (S)
    Changed
  • Confidentiality (C)
    Low
  • Integrity (I)
    Low
  • Availability (A)
    None