cvedb.io
CVE-2021-35209
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2021-07-02T19:15:08.460 · Last modified 2026-06-17T03:57:18.203

Summary

An issue was discovered in ProxyServlet.java in the /proxy servlet in Zimbra Collaboration Suite 8.8 before 8.8.15 Patch 23 and 9.x before 9.0.0 Patch 16. The value of the X-Host header overwrites the value of the Host header in proxied requests. The value of X-Host header is not checked against the whitelist of hosts Zimbra is allowed to proxy to (the zimbraProxyAllowedDomains setting).

Affected products

zimbra — collaboration

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.