Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability
Synacor · Zimbra Collaboration Suite
The Synacor Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 contains a server-side request forgery flaw in its WebEx zimlet component, which is exposed when that zimlet is installed and the zimlet JSP is enabled. An attacker with network access can exploit it without authentication or user interaction to make the server issue requests to arbitrary destinations.
Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 2/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.How attackers get in
What they do
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 4 years after disclosure.
- Disclosedday 0
- First seen exploitedVulnCheck KEV evidence+4 yrs
- Added to CISA KEVEU database agrees+6 yrs
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 2 cited passages 2Initial AccessTA0001
Exploits public-facing webmail server via SSRF
allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled
Command and ControlTA0011
SSRF lets attacker proxy requests internally
allows SSRF when WebEx zimlet is installed
Detection
0 rules for this CVE · 171 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2020-7796 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploit Public-Facing ApplicationT1190149 general rules
- Arcadyan Router Exploitationscriticaltest
- Citrix ADS Exploitation CVE-2020-8193 CVE-2020-8195criticaltest
- Citrix Netscaler Attack CVE-2019-19781criticaltest
- Confluence Exploitation CVE-2019-3398criticaltest
- CVE-2010-5278 Exploitation Attemptcriticaltest
- CVE-2020-0688 Exchange Exploitation via Web Logcriticaltest
- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
ProxyT109022 general rules
- Communication To LocaltoNet Tunneling Service Initiatedhightest
- Communication To LocaltoNet Tunneling Service Initiated - Linuxhightest
- Communication To Ngrok Tunneling Service - Linuxhightest
- Communication To Ngrok Tunneling Service Initiatedhightest
- HackTool - Htran/NATBypass Executionhightest
- Malicious IP Address Sign-In Failure Ratehightest
- Malicious IP Address Sign-In Suspicioushightest
- Ngrok Usage with Remote Desktop Servicehightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX