XML External Entity (XXE) Injection Affecting org.jenkins-ci.plugins:swarm package, versions [,3.17)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.26% (67th percentile)

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  • Snyk IDSNYK-JAVA-ORGJENKINSCIPLUGINS-449960
  • published17 Jun 2019
  • disclosed30 Apr 2019
  • creditPeter Adkins of Cisco Umbrella

Introduced: 30 Apr 2019

CVE-2019-10309  (opens in a new tab)
CWE-611  (opens in a new tab)

How to fix?

Upgrade org.jenkins-ci.plugins:swarm to version 3.17 or higher.

Overview

org.jenkins-ci.plugins:swarm is a Jenkins Self Organizing Swarm Plug In Modules.

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection. UDP broadcasts used by the plugin to discover Jenkins masters do not prevent XML External Entity processing when processing the responses, allowing unauthorized attackers on the same network to read arbitrary files from Swarm clients.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

CVSS Scores

version 3.1