CVE-2021-39181

Unsafe Deserialization of User Data Using XStream

Description

OpenOlat is a web-based learning management system (LMS). Prior to version 15.3.18, 15.5.3, and 16.0.0, using a prepared import XML file (e.g. a course) any class on the Java classpath can be instantiated, including spring AOP bean factories. This can be used to execute code arbitrary code by the attacker. The attack requires an OpenOlat user account with the authoring role. It can not be exploited by unregistered users. The problem is fixed in versions 15.3.18, 15.5.3, and 16.0.0. There are no known workarounds aside from upgrading.

Category

8.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.55%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: OpenOLAT OpenOLAT
Published at:
Updated at:

References

Link Tags
https://github.com/OpenOLAT/OpenOLAT/security/advisories/GHSA-596v-3gwh-2m9w third party advisory
https://github.com/OpenOLAT/OpenOLAT/commit/3f219ac457afde82e3be57bc614352ab92c05684 third party advisory patch
https://jira.openolat.org/browse/OO-5548 permissions required

Frequently Asked Questions

What is the severity of CVE-2021-39181?
CVE-2021-39181 has been scored as a high severity vulnerability.
How to fix CVE-2021-39181?
To fix CVE-2021-39181, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-39181 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-39181 is being actively exploited. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-39181?
CVE-2021-39181 affects OpenOLAT OpenOLAT.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.