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Threats / Realtek / CVE-2021-35394
CVE-2021-35394 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Realtek Jungle Software Development Kit (SDK) vulnerability

Realtek Jungle SDK contains multiple memory corruption vulnerabilities enabling remote code execution.

Verdict

Today item — known-exploited.

Memory corruption flaws in Realtek Jungle SDK allow unauthenticated remote attackers to execute arbitrary code. High EPSS score and active exploitation indicate immediate risk to deployed systems.

CISA KEV Yes · 2021-12-103EPSS 0.99857 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
18 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 2021-12-10).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.99857 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Realtek, Jungle Software Development Kit (SDK). Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-78 OS Command Injection, CWE-138 CWE-138 — weakness family: Injection.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 malicious input targeting memory corruption weaknesses in the SDK to trigger code execution.
Business
Attacker gains unauthorized code execution on systems running vulnerable Realtek Jungle SDK components.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I establish persistent access and move laterally within the compromised network infrastructure.
Business
Organization faces potential data exfiltration, system compromise, and operational disruption across connected devices.
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)
  • 18 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.