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Threats / Synacor / CVE-2020-7796
CVE-2020-7796 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Synacor Zimbra Collaboration Suite vulnerability

Synacor Zimbra Collaboration Suite contains a server-side request forgery vulnerability when the WebEx zimlet is installed and zimlet JSP is enabled, allowing remote exploitation.

Verdict

Today item — known-exploited.

A server-side request forgery flaw in Zimbra Collaboration Suite enables attackers to make unauthorized requests from the affected server to internal or external systems, potentially bypassing network controls and accessing restricted resources.

CISA KEV Yes · 2026-02-173EPSS 0.85416 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
563 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 2026-02-17).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.85416 — 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. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-918 Server-Side Request Forgery (SSRF).CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
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 craft a malicious request targeting the WebEx zimlet JSP endpoint to trigger server-side request forgery.
Business
Attackers gain the ability to probe internal network topology and access services restricted by firewall rules.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I leverage the SSRF to access internal metadata services or cloud provider credentials exposed on the server.
Business
Compromise of authentication credentials or sensitive configuration data stored on or accessible from the mail server.
3

Lateral reach — past segmentation narrative 3

Attacker
I use the server as a proxy to attack other internal systems or services that trust the mail server's network position.
Business
Lateral movement into backend infrastructure, potentially compromising databases, file servers, or other critical systems.
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)
  • EPSS probability (FIRST)
  • 563 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • 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.