Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
Synacor · Zimbra Collaboration Suite (ZCS)
CVSS 9.8
EPSS 100%
4 public exploits
Fix deadline passed 10 July 2022
What it is
Synacor Zimbra Collaboration Suite (ZCS) contains an improper restriction of XML external entity (XXE) vulnerability in the mailboxd component.
Why we say that
- EPSS puts exploitation in the next 30 days at 100%
- 4 public exploits published
- CISA's federal remediation deadline (2022-07-10) has passed
- CVSS 9.8 critical
- 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 updates per vendor instructions.
Public exploit code
Indexed from Exploit-DB. Presence of code raises urgency; absence does not mean safety.
- 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…