CVE-2021-35209: SSRF
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 Software
Event History
Frequently Asked Questions
What is the vulnerability identified as CVE-2021-35209?
CVE-2021-35209 is an issue 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.
What is the severity of CVE-2021-35209?
The severity of CVE-2021-35209 is critical, with a CVSS score of 9.8.
How does CVE-2021-35209 affect Zimbra Collaboration Suite?
CVE-2021-35209 allows the value of the X-Host header to overwrite the value of the Host header in proxied requests in Zimbra Collaboration Suite.
Which versions of Zimbra Collaboration Suite are affected by CVE-2021-35209?
The vulnerability affects Zimbra Collaboration Suite 8.8 before 8.8.15 Patch 23 and 9.x before 9.0.0 Patch 16.
How can I fix CVE-2021-35209 in Zimbra Collaboration Suite?
To fix CVE-2021-35209, upgrade Zimbra Collaboration Suite to version 8.8.15 Patch 23 or 9.0.0 Patch 16.