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Threats / Cisco / CVE-2025-20393
CVE-2025-20393 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Cisco Multiple Products vulnerability

Cisco Secure Email Gateway, Secure Email, AsyncOS Software, and Web Manager appliances contain an improper input validation vulnerability enabling arbitrary command execution with root privileges on affected systems.

Verdict

Today item — known-exploited.

An unauthenticated or low-privileged attacker can exploit improper input validation to execute arbitrary commands with root-level access on vulnerable Cisco email and web management appliances, potentially compromising email infrastructure and administrative systems.

CISA KEV Yes · 2025-12-173EPSS 0.2906 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
14 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 2025-12-17).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.2906 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, Multiple Products. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.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 identify and craft malicious input that bypasses validation controls on the appliance interface.
Business
Email security infrastructure becomes a direct attack vector for command injection and system compromise.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I submit the crafted payload to execute arbitrary commands with root privileges on the underlying operating system.
Business
Complete control of the appliance enables data exfiltration, lateral movement, and persistent access to email systems.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish persistence and pivot to connected networks and systems relying on the compromised appliance.
Business
Organizational email communications, authentication systems, and connected infrastructure face compromise and operational disruption.
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)
  • 14 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by cisco (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 ciscoCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.