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).
{
"versions": [
{
"introduced": "0"
},
{
"last_affected": "8.8.15-NA"
},
{
"introduced": "0"
},
{
"last_affected": "9.0.0-NA"
}
]
}