CVE-2021-39152
Description
A flaw was found in xstream, a simple library used to serialize objects to XML and back again. This flaw allows a remote attacker to request data from internal resources that are not publicly available by manipulating the processed input stream with Java runtime versions 14 to 8. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Statement
Users who follow the recommended security framework with a whitelist to limit the types to the minimum required should not be affected. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.18.
OpenShift Container Platform (OCP) delivers the Jenkins LTS package with bundled XStream library. Due to JEP-200 [1] and JEP-228 [2] Jenkins projects, the OCP Jenkins package is not affected by this flaw.
This version of the XStream library will be delivered in future Jenkins releases.
[1] https://github.com/jenkinsci/jep/blob/master/jep/200/README.adoc [2] https://github.com/jenkinsci/jep/blob/master/jep/228/README.adoc#security
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.5 | 8.5 | 8.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Changed | Changed | Changed |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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