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Threats / Synacor / CVE-2022-37042
CVE-2022-37042 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Synacor Zimbra Collaboration Suite (ZCS) vulnerability

Synacor Zimbra Collaboration Suite contains an authentication bypass in MailboxImportServlet that can be chained with CVE-2022-27925 to achieve unauthenticated remote code execution.

Verdict

Today item, not a backlog item.

This vulnerability enables attackers to bypass authentication controls and execute arbitrary code remotely without credentials. Active exploitation in ransomware campaigns demonstrates immediate operational risk to deployed Zimbra infrastructure.

CISA KEV Yes · 2022-08-113Ransomware use Flagged3EPSS 0.88256 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
880 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 2022-08-11), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.88256 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Synacor, Zimbra Collaboration Suite (ZCS). Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-23 Relative Path Traversal — weakness family: Path traversal / file.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-23 · Relative Path TraversalPath traversal / file
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

Front door — unauthenticated access narrative 1

Attacker
I bypass authentication checks in the MailboxImportServlet endpoint to gain unauthorized access.
Business
Security perimeter is compromised; access controls fail to prevent unauthorized entry.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I chain this bypass with CVE-2022-27925 to execute arbitrary code on the target system.
Business
Complete system compromise occurs; attackers gain code execution capability within production infrastructure.
3

Lateral reach — past segmentation narrative 3

Attacker
I deploy ransomware payloads across the compromised Zimbra environment and connected systems.
Business
Critical business data is encrypted and held for ransom; operations cease; recovery costs and ransom demands create severe financial impact.
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

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • Ransomware-use flag (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 880 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.