CVE-2021-34359 json
Stored XSS Vulnerability in Proxy Server
published 4y ago modified 4mo ago also EUVD-2021-21019
- cvss
- 6.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running Proxy Server. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of Proxy Server: QTS 4.5.x: Proxy Server 1.4.2 ( 2021/12/30 ) and later
Patch / fix
- QNAP Systems Inc. Proxy Server 1.4.2 ( 2021/12/30 )
Is CVE-2021-34359 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.62% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.9 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Affected products
- QNAP Systems Inc. Proxy Server
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
qnap.com
/en/security-advisory/qsa-22-04
vendor-advisory
Sources
- CVE List CVE-2021-34359
- NVD CVE-2021-34359
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.