{"id":86605,"date":"2026-03-04T12:35:52","date_gmt":"2026-03-04T12:35:52","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-53645-denial-of-service-vulnerability-in-zimbra-collaboration-suite","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-53645-denial-of-service-vulnerability-in-zimbra-collaboration-suite\/","title":{"rendered":"CVE-2025-53645: Denial of Service Vulnerability in Zimbra Collaboration Suite<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

This report details a high-severity vulnerability, CVE-2025-53645, found in the Zimbra Collaboration Suite (ZCS). This vulnerability affects versions of ZCS prior to 9.0.0 Patch 46, 10.0.x before 10.0.15, and 10.1.x before 10.1.9. It poses a significant threat as it allows an unauthenticated remote attacker to cause a denial of service (DoS) condition by sending specially crafted GET requests.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-53645
\nSeverity: High, CVSS Score 7.5
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Denial of Service, potential system compromise, or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Zimbra Collaboration Suite | Before 9.0.0 Patch 46
\nZimbra Collaboration Suite | 10.0.x before 10.0.15
\nZimbra Collaboration Suite | 10.1.x before 10.1.9<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability arises due to the improper handling of excessive, comma-separated path segments in both the Webmail interface and the Admin Console of the Zimbra Collaboration Suite. An unauthenticated remote attacker can exploit this vulnerability by sending specially crafted GET requests with excessive path segments. This triggers redundant processing and inflated responses, leading to uncontrolled resource consumption and ultimately, denial of service.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Below is a conceptual example of how an attacker might exploit this vulnerability through a GET request.<\/p>\n

GET \/zimbra\/,\/,\/,\/,\/,\/,\/,\/,\/,\/,\/,\/,\/,\/,\/ HTTP\/1.1\nHost: target.example.com<\/code><\/pre>\n
This request floods the Zimbra server with redundant processing tasks, leading to resource exhaustion and ultimately, a denial of service.<\/p>\n
Mitigation Guidance<\/strong><\/p>\n
The best course of action to mitigate this vulnerability is to apply the vendor-supplied patch. If applying the patch is not immediately feasible, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. It is highly recommended to prioritize the patch application to ensure the security of the affected systems.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview This report details a high-severity vulnerability, CVE-2025-53645, found in the Zimbra Collaboration Suite (ZCS). This vulnerability affects versions of ZCS prior to 9.0.0 Patch 46, 10.0.x before 10.0.15, and 10.1.x before 10.1.9. It poses a significant threat as it allows an unauthenticated remote attacker to cause a denial of service (DoS) condition by sending […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-86605","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t