Threats / Synacor / CVE-2022-24682
CVE-2022-24682
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Synacor Zimbra Collaborate Suite (ZCS) vulnerability
Synacor Zimbra Collaborate Suite contains a cross-site scripting vulnerability in the Calendar feature allowing arbitrary code execution. The flaw is actively exploited in ransomware campaigns.
Verdict
Today item, not a backlog item.
A stored or reflected XSS in the Calendar component permits attackers to inject malicious scripts that execute in victim browsers with user privileges. Active exploitation in ransomware operations indicates high real-world risk despite no CVSS score assignment.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
12 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-02-25), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.3106 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Synacor, Zimbra Collaborate Suite (ZCS). Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-79 Cross-site Scripting (XSS), CWE-116 CWE-116 — weakness family: Web / client.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious calendar event or link containing JavaScript payload targeting Zimbra users.
Business
Attackers gain initial code execution within the user's browser session and trusted domain context.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary actions as the logged-in user, such as stealing session tokens or modifying calendar data.
Business
User accounts are compromised, enabling lateral movement and persistence within the organization.
3
Lateral reach — past segmentation narrative 3
Attacker
I deploy ransomware payloads or establish command-and-control callbacks from compromised endpoints.
Business
Systems are encrypted or exfiltrated; operations halt and ransom demands follow.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05