Vulnerability · Published Jul 2, 2021 · Assigned by mitre

CVE-2021-35209

Critical 9.8

In plain English

A critical-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.0% (higher than 87% of all known vulnerabilities).

Severity (CVSS NVD)9.8Critical

Exploit odds (30 days)3.0%top 12.6% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

References

https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories x_refsource_MISC
https://wiki.zimbra.com/wiki/Security_Center x_refsource_MISC
https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16 x_refsource_MISC
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23 x_refsource_MISC
https://blog.sonarsource.com/zimbra-webmail-compromise-via-email x_refsource_MISC