Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vulnerability
Synacor · Zimbra Collaboration Suite (ZCS)
CVSS 7.5
EPSS 81%
6 public exploits
Fix deadline passed 28 July 2025
What it is
Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery (SSRF) vulnerability via the ProxyServlet component.
Why we say that
- EPSS puts exploitation in the next 30 days at 81%
- 6 public exploits published
- CISA's federal remediation deadline (2025-07-28) has passed
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public exploit code
Indexed from Exploit-DB. Presence of code raises urgency; absence does not mean safety.
- Zimbra < 8.8.11 - XML External Entity Injection / Server-Side Request Forgery
- Zimbra < 8.8.11 - XML External Entity Injection / Server-Side Request Forgery
- Zimbra Collaboration - Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit)
- Zimbra Collaboration - Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit)
- Zimbra Collaboration - Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit)
- Zimbra Collaboration - Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit)
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:
- The Electoral Commission Reprimand issued to the Electoral Commission in respect of Articles 5(1)(f) and 32(1)(b). Between 24 August 2021 and 27 October 20…
- Gain Capital UK Limited Gain Capital UK have been issued a Reprimand in respect of Articles 32 (2) and 32 (1) (b). An unauthorised third party leveraged a…
- Chartered Institute for Securities & Investment An unauthorised third party exploited a known vulnerability in the Sitefinity software to leverage a bruteforce attack to upload a…