CVE-2021-44052: QNAP QTS

High severity, CVSS 8.1. EPSS: 1.6% chance of exploitation in the next 30 days.

An improper link resolution before file access ('Link Following') vulnerability has been reported to affect QNAP device running QuTScloud, QuTS hero, and QTS. If exploited, this vulnerability allows remote attackers to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. We have already fixed this vulnerability in the following versions of QuTScloud, QuTS hero, and QTS: QuTScloud c5.0.1.1998 and later QuTS hero h4.5.4.1971 build 20220310 and later QuTS hero h5.0.0.1986 build 20220324 and later QTS 4.3.4.1976 build 20220303 and later QTS 4.3.3.1945 build 20220303 and later QTS 4.2.6 build 20220304 and later QTS 4.3.6.1965 build 20220302 and later QTS 5.0.0.1986 build 20220324 and later QTS 4.5.4.1991 build 20220329 and later

Affected products

• QNAP QTS: from 5.0.0.1716, before 5.0.0.1986 (fixed in 5.0.0.1986); from 4.3.3.0174, before 4.3.3.1945 (fixed in 4.3.3.1945); from 4.3.4.0899, before 4.3.4.1976 (fixed in 4.3.4.1976); from 4.3.6.0895, before 4.3.6.1965 (fixed in 4.3.6.1965); from 4.4.0.0883, before 4.5.4.1991 (fixed in 4.5.4.1991); version 4.2.6 only
• QNAP Quts Hero: before h4.5.4.1771 (fixed in h4.5.4.1771); from h5.0.0.1772, before h5.0.0.1986 (fixed in h5.0.0.1986)
• QNAP Qutscloud: before c5.0.1.1998 (fixed in c5.0.1.1998)

Published 2022-05-05. Last modified 2026-06-17.