CVE-2021-34357

Name: CVE-2021-34357
Creator: NVD / NIST
Published: 2021-11-13T01:15:07.557+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.69%

Last modified Jun 17, 2026

CVE-2021-34357 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QmailAgent. If exploited, this vulnerability allows remote attackers to inject malicious code. EPSS estimates a 0.69% chance of exploitation in the next 30 days.

Description

A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QmailAgent. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of QmailAgent: QmailAgent 3.0.2 ( 2021/08/25 ) and later

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.69%

48.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Qnap	Qmailagent	< 3.0.2

References

https://www.qnap.com/en/security-advisory/qsa-21-47Vendor Advisory
https://www.qnap.com/en/security-advisory/qsa-21-47Vendor Advisory

Timeline

Published: Nov 13, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34357?

How severe is CVE-2021-34357?

CVE-2021-34357 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34357?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34357?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST