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Fencer Intel
high 8.8

CVE-2021-28798 json

Relative Path Traversal Vulnerability in QTS and QuTS hero

published 5y ago modified 4mo ago also EUVD-2021-15454

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

A relative path traversal vulnerability has been reported to affect QNAP NAS running QTS and QuTS hero. If exploited, this vulnerability allows attackers to modify files that impact system integrity. QNAP have already fixed this vulnerability in the following versions: QTS 4.5.2.1630 Build 20210406 and later QTS 4.3.6.1663 Build 20210504 and later QTS 4.3.3.1624 Build 20210416 and later QuTS hero h4.5.2.1638 Build 20210414 and later QNAP NAS running QTS 4.5.3 are not affected.

Patch / fix

  • QNAP Systems Inc. QTS 4.3.3.1624 Build 20210416, 4.3.6.1663 Build 20210504, 4.5.2.1630 Build 20210406, 4.5.3
  • QNAP Systems Inc. QuTS hero h4.5.2.1638 Build 20210414

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Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • QNAP Systems Inc. QTS
  • QNAP Systems Inc. QuTS hero

Classification

Weakness
  • CWE-284 Improper Access Control
  • CWE-23 Relative Path Traversal
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Intel 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.