Cyber Resilience

CVE-2021-35207

Medium

Published: 02 July 2021

Published
02 July 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0106 78.0th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-35207 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Zimbra Collaboration. Its CVSS base score is 6.1 (Medium).

Operationally, ranked in the top 22.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

An issue was discovered in Zimbra Collaboration Suite 8.8 before 8.8.15 Patch 23 and 9.0 before 9.0.0 Patch 16. An XSS vulnerability exists in the login component of Zimbra Web Client, in which an attacker can execute arbitrary JavaScript by…

more

adding executable JavaScript to the loginErrorCode parameter of the login url.

CWE(s)
CWE-79

Related Threats

Threat-Actor AttributionAI

Winter Vivern (G1035)
Winter Vivern Uses Zimbra Vulnerability to Target NATO Email | Proofpoint US

Affected Assets

zimbra
collaboration
8.8.15, 9.0.0 · 8.8 — 8.8.15

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation
addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering
addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References