basicsecurity.net
Proof, not just disclosure.
Threats / Citrix / CVE-2020-8195
CVE-2020-8195 · EUVD no mirror located · GCVE no mirror located Verified 2026-08-04

Citrix Application Delivery Controller (ADC), Gateway, and S vulnerability

Citrix ADC, Gateway, and SD-WAN WANOP appliances contain an information disclosure vulnerability allowing unauthorized access to sensitive data.

Verdict

Today item — known-exploited.

An input validation flaw in Citrix network appliances enables attackers to extract confidential information. Active exploitation in the wild demonstrates immediate risk to organizations running affected infrastructure.

CISA KEV Yes · 2021-11-035EPSS 0.33263 (verify live)6CVSS 6.5 (CISA)4CISA SSVC Exploitation: active · Automatable: no · Impact: partial4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
8 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).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.33263 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) · Affected: Citrix, Application Delivery Controller (ADC), Gateway, and SD-WAN WANOP Appliance. 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.
CISA-ADP ↗Reported
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CVE.org ↗Reported
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: partialCISA'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.
CISA-ADP ↗Reported
Currency of the record
CISA added this to its KEV catalog 481 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 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 malformed requests targeting the input validation weakness to bypass access controls.
Business
Sensitive configuration data, credentials, or operational details become exposed to unauthorized parties.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I exfiltrate disclosed information to map network topology, identify secondary targets, or obtain authentication material.
Business
Compromised data accelerates lateral movement and increases exposure surface across the organization's infrastructure.
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)
  • 8 reported-exploitation source(s)
  • CVSS 6.5 — CISA-assigned (CVE.org ADP)
  • CISA SSVC triage disposition (CVE.org ADP)
  • CWE weakness mapping — CNA-assigned (CVE.org)
  • Catalogued by hackerone (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 hackeroneCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.