CVE-2021-43795: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in com.linecorp.armeria:armeria

Severity: medium (CVSS 5.0 v2.0)
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: none known
Published: 2021-12-02 · updated 2026-06-17
Weakness: CWE-22

Description

Armeria is an open source microservice framework. In affected versions an attacker can access an Armeria server's local file system beyond its restricted directory by sending an HTTP request whose path contains `%2F` (encoded `/`), such as `/files/..%2Fsecrets.txt`, bypassing Armeria's path validation logic. Armeria 1.13.4 or above contains the hardened path validation logic that handles `%2F` properly. This vulnerability can be worked around by inserting a decorator that performs an additional validation on the request path.

Affected products

line armeria: before 1.13.4 — fixed in 1.13.4

How to fix

Upgrade to a fixed version: line armeria 1.13.4. Check the vendor advisory for mitigations.

References

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