CVE-2021-34357
Reflected XSS Vulnerability in QmailAgent
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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Reflected XSS Vulnerability in QmailAgent
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
- Record
CVE-2021-34357- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-21017
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
- Record
EUVD-2021-21017- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gfgx-cxc3-v57c No score
A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running...
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
- Record
GHSA-gfgx-cxc3-v57c- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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
- Record
CVE-2021-34357- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34357 is a medium vulnerability (CVSS 6.9) in Qnap Qmailagent, published November 13, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.71%, the 53rd percentile. No source names a fixed version.