CVE-2021-32769: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in micronaut-core

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-07-16 · updated 2026-06-17
Weakness: CWE-22

Description

Micronaut is a JVM-based, full stack Java framework designed for building JVM applications. A path traversal vulnerability exists in versions prior to 2.5.9. With a basic configuration, it is possible to access any file from a filesystem, using "/../../" in the URL. This occurs because Micronaut does not restrict file access to configured paths. The vulnerability is patched in version 2.5.9. As a workaround, do not use `**` in mapping, use only `*`, which exposes only flat structure of a directory not allowing traversal. If using Linux, another workaround is to run micronaut in chroot.

Affected products

micronaut-projects micronaut-core: before 2.5.9 — fixed in 2.5.9

How to fix

Upgrade to a fixed version: micronaut-projects micronaut-core 2.5.9. Check the vendor advisory for mitigations.

References

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