An issue was discovered in ProxyServlet.java in the /proxy servlet in Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0. The value of the X-Forwarded-Host header overwrites the value of the Host header in proxied requests. The value of X-Forwarded-Host header is not checked against the whitelist of hosts that ZCS is allowed to proxy to (the zimbraProxyAllowedDomains setting).
| Software | From | Fixed in |
|---|---|---|
| zimbra / collaboration | 9.0.0 | 9.0.0.x |
| zimbra / collaboration | 8.8.15 | 8.8.15.x |