Threats / Adobe / CVE-2018-4878
CVE-2018-4878
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Adobe Flash Player vulnerability
Adobe Flash Player use-after-free vulnerability enabling remote code execution. Actively exploited in ransomware campaigns.
Verdict
Today item, not a backlog item.
Use-after-free in Flash Player permits arbitrary code execution when processing malicious content. High EPSS score and confirmed wild exploitation in ransomware operations indicate immediate threat to unpatched systems.
CISA KEV Yes · 2021-11-034Ransomware use Flagged4EPSS 0.89532 (verify live)5Exploit Public PoC6CVSS 7.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
21 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 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.89532 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) · Affected: Adobe, Flash Player. 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-416 Use After Free — weakness family: Memory safety.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: totalCISA'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 1366 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.
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
Craft malicious Flash content that triggers use-after-free memory corruption during parsing or playback.
Business
End-user systems become compromised entry points for ransomware deployment and data exfiltration.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Deliver weaponized Flash file via email, watering hole, or malicious advertisement to target victims.
Business
Ransomware operators gain execution capability to encrypt critical business data and demand payment.
3
Lateral reach — past segmentation narrative 3
Attacker
Execute arbitrary code with user privileges to establish persistence and lateral movement within networks.
Business
Organizational infrastructure becomes compromised; operational continuity threatened by encryption and containment costs.
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