What is CVE-2021-21434?

CVE-2021-21434 is a low-severity vulnerability in Otrs Survey, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2021-02-08.

How severe is CVE-2021-21434?

Low severity. CVSS v3 base score is 3.5 out of 10.

XSS in Otrs Survey

CVE-2021-21434

Survey administrator can craft a survey in such way that malicious code can be executed in the agent interface (i.e. another agent who wants to make changes in the survey). This issue affects: OTRS AG Survey 6.0.x version 6.0.20 and prior versions; 7.0.x version 7.0.19 and prior versions.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-02-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (49.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Otrs Survey
Otrs Ag Survey — versions 6.0.x, 7.0.x

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

otrs.com/release-notes/otrs-security-advisory-2021-01/ (Vendor Advisory)

Frequently asked questions

What is CVE-2021-21434?: CVE-2021-21434 is a low-severity vulnerability in Otrs Survey, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2021-02-08.
How severe is CVE-2021-21434?: Low severity. CVSS v3 base score is 3.5 out of 10.