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Fencer Vulns
high 8.1

CVE-2021-39180 json

Path Traversal in Archive Handling Leading to Code Execution

published 2021-08-31 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-25574

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

OpenOLAT is a web-based learning management system (LMS). A path traversal vulnerability exists in versions prior to 15.3.18, 15.5.3, and 16.0.0. Using a specially prepared ZIP file, it is possible to overwrite any file that is writable by the application server user (e.g. the tomcat user). Depending on the configuration this can be limited to files of the OpenOlat user data directory, however, if not properly set up, the attack could also be used to overwrite application server config files, java code or even operating system files. The attack could be used to corrupt or modify any OpenOlat file such as course structures, config files or temporary test data. Those attack would require in-depth knowledge of the installation and thus more theoretical. If the app server configuration allows the execution of jsp files and the path to the context is known, it is also possible to execute java code. If the app server runs with the same user that is used to deploy the OpenOlat code or has write permissions on the OpenOlat code files and the path to the context is know, code injection is possible. The attack requires an OpenOlat user account to upload a ZIP file and trigger the unzip method. 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.

Patch / fix

  • frentix openolat 15.3.18, 15.5.3

Exploit prediction

2.44% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C

Affected products

  • OpenOLAT OpenOLAT

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.