UpHeron
All vulnerabilities

Servers and applications

CVE-2021-35209

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).

Severity
Critical 9.8
Published
2 Jul 2021
Last changed
17 Jun 2026
Added to UpHeron
1 Nov 2026
Fixed in
8.8.15
Sources
NVD

Affected software

SoftwareAffected versions
Zimbra CollaborationServers and applications · cpe:a:zimbra:collaboration
  • Version 9.0.0-p12
  • Version 9.0.0-p11
  • Version 9.0.0-p10
  • Version 9.0.0-p9
All 34 release lines
  • From 8.8 before 8.8.15
  • Version 8.8.15
  • Version 8.8.15-p1
  • Version 8.8.15-p2
  • Version 8.8.15-p3
  • Version 8.8.15-p4
  • Version 8.8.15-p5
  • Version 8.8.15-p6
  • Version 8.8.15-p7
  • Version 8.8.15-p8
  • Version 8.8.15-p9
  • Version 8.8.15-p10
  • Version 8.8.15-p11
  • Version 8.8.15-p12
  • Version 8.8.15-p13
  • Version 8.8.15-p14
  • Version 8.8.15-p15
  • Version 8.8.15-p16
  • Version 8.8.15-p17
  • Version 8.8.15-p18
  • Version 8.8.15-p19
  • Version 9.0.0
  • Version 9.0.0-p1
  • Version 9.0.0-p2
  • Version 9.0.0-p3
  • Version 9.0.0-p4
  • Version 9.0.0-p5
  • Version 9.0.0-p6
  • Version 9.0.0-p7
  • Version 9.0.0-p8
  • Version 9.0.0-p9
  • Version 9.0.0-p10
  • Version 9.0.0-p11
  • Version 9.0.0-p12

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2021-35209
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2021-35209