basicsecurity.net
Proof, not just disclosure.
Threats / Cisco / CVE-2018-0147
CVE-2018-0147 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Cisco Secure Access Control System (ACS) vulnerability

Insecure Java deserialization in Cisco Secure Access Control System (ACS) allows unauthenticated remote attackers to execute arbitrary commands on affected devices.

Verdict

Today item — known-exploited.

An unauthenticated remote attacker can exploit unsafe deserialization of user-supplied input to achieve remote code execution on Cisco ACS systems without requiring valid credentials or authentication.

CISA KEV Yes · 2022-03-253EPSS 0.18554 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
3 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 2022-03-25).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.18554 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, Secure Access Control System (ACS). 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 craft a malicious serialized Java object and send it to the vulnerable ACS service over the network.
Business
The organization's access control infrastructure becomes a direct attack vector requiring no authentication.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
The ACS application deserializes my malicious payload, triggering arbitrary code execution with the privileges of the ACS process.
Business
Attackers gain command execution on a critical authentication and authorization system.
3

Lateral reach — past segmentation narrative 3

Attacker
I execute system commands to establish persistence, exfiltrate credentials, or pivot to other network resources.
Business
The compromise of ACS enables lateral movement throughout the network and potential theft of authentication credentials.
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)
  • 3 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.