SSRF in Synacor Zimbra Collaboration Suite
CVE-2019-9621
Zimbra Collaboration Suite before 8.6 patch 13, 8.7.x before 8.7.11 patch 10, and 8.8.x before 8.8.10 patch 7 or 8.8.x before 8.8.11 patch 3 allows SSRF via the ProxyServlet component.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.810 (99.6th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.810 · newest: 0.810 · change: 0.000
Affected products
- Synacor Zimbra Collaboration Suite — versions 8.6.0, 8.7.11, 8.8.9
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: 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 proof-of-concept exploits
References
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories (Vendor Advisory)
- wiki.zimbra.com/wiki/Security_Center (Release Notes, Vendor Advisory)
- bugzilla.zimbra.com/show_bug.cgi (Issue Tracking)
- www.rapid7.com/db/modules/exploit/linux/http/zimbra_xxe_rce (Exploit, Third Party Advisory)
- packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autodiscover-Servlet-… (Exploit, VDB Entry, Third Party Advisory)
- www.exploit-db.com/exploits/46693/ (Exploit, VDB Entry, Third Party Advisory, exploit)
- blog.zimbra.com/2019/03/9826/ (Vendor Advisory)
- blog.tint0.com/2019/03/a-saga-of-code-executions-on-zimbra.html (Third Party Advisory)
- packetstormsecurity.com/files/153190/Zimbra-XML-Injection-Server-Side-Request-F… (Exploit, VDB Entry, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2019-9621?
- CVE-2019-9621 is a high-severity vulnerability in Synacor Zimbra Collaboration Suite, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.5/10. Published 2019-04-30.
- How severe is CVE-2019-9621?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2019-9621 known to be exploited?
- Yes. CVE-2019-9621 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-07-07), indicating it is being actively exploited. 16 public proof-of-concept repositories are indexed.