CVE-2021-38693: Path Traversal in thttpd

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-05-05 · updated 2026-06-17
Weakness: CWE-22

Description

A path traversal vulnerability has been reported to affect QNAP device running QuTScloud, QuTS hero, QTS, QVR Pro Appliance. If exploited, this vulnerability allows attackers to read the contents of unexpected files and expose sensitive data. We have already fixed this vulnerability in the following versions of QuTScloud, QuTS hero, QTS, QVR Pro Appliance: QuTScloud c5.0.1.1949 and later QuTS hero h5.0.0.1949 build 20220215 and later QuTS hero h4.5.4.1951 build 20220218 and later QTS 5.0.0.1986 build 20220324 and later QTS 4.5.4.1991 build 20220329 and later

Affected products

QNAP QTS: before 4.5.4.1991; from 5.0.0.1716 before 5.0.0.1986 — fixed in 4.5.4.1991, 5.0.0.1986
QNAP Systems Inc. QuTS hero: from h5.0.0.1772 before h5.0.0.1949 — fixed in h5.0.0.1949
QNAP Systems Inc. QuTScloud: before c5.0.1.1949 — fixed in c5.0.1.1949

How to fix

Upgrade to a fixed version: QNAP QTS 4.5.4.1991, 5.0.0.1986; QNAP Systems Inc. QuTS hero h5.0.0.1949; QNAP Systems Inc. QuTScloud c5.0.1.1949. Check the vendor advisory for mitigations.

References

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