XML External Entity (XXE) Injection Affecting org.opencastproject:opencast-ingest-service-impl package, versions [,9.6)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.07% (32nd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk ID SNYK-JAVA-ORGOPENCASTPROJECT-1305815
  • published 16 Jun 2021
  • disclosed 16 Jun 2021
  • credit Unknown

How to fix?

Upgrade org.opencastproject:opencast-ingest-service-impl to version 9.6 or higher.

Overview

org.opencastproject:opencast-ingest-service-impl is a free and open source solution for automated video capture and distribution at scale.

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection. An attacker could easily execute a (seemingly permanent) denial of service attack via a billion laughs attack (XML bomb). To exploit this, users need to have ingest privileges, limiting the group of potential attackers.

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.

References

CVSS Scores

version 3.1
Expand this section

Snyk

8.1 high
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    High
  • Availability (A)
    High
Expand this section

NVD

6.5 medium