Threats / Synacor / CVE-2022-24682
CVE-2022-24682
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
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.
CISA KEV Yes · 2022-02-254Ransomware use Flagged4EPSS 0.3106 (verify live)5CVSS 6.1 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: partial3Exploit Public PoC / detection · nuclei template11
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
CVSS 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N) · Affected: Synacor, Zimbra Collaborate Suite (ZCS). Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
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 (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: partialCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 16 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
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