CVE Intelligence
CISA KEV Medium Authentication exploit reference

CVE-2020-8193 — Citrix ADC, Gateway, and SD-WAN WANOP Appliance Authorization Bypass Vulnerability

Improper access control in Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.14 and 10.5-70.18 and Citrix SDWAN WAN-OP versions before 11.1.1a, 11.0.3d and 10.2.7 allows unauthenticated access to certain URL endpoints.

Published Jul 10, 2020 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: hackerone

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Nov 3, 2021 Detection templates (Nuclei) · 1
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (nuclei)+4
  • EPSS 88.4% (30-day exploitation probability)+15
  • Technical severity (medium)+3
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Nov 3, 2021
EPSS FIRST
88.41%
ahead of 100% of scored CVEs · Oct 14, 2026
Affects
Citrix
Application Delivery Controller Firmware and 3 more
CVSS base
6.5
Medium · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: May 3, 2022 — passed 1626 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Citrix Application Delivery Controller Firmware, Citrix Gateway Firmware, Citrix Netscaler Gateway Firmware…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
  6. Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Citrix Application Delivery Controller Firmware ≥ 10.5 and < 10.5-70.18≥ 11.1 and < 11.1-64.14≥ 12.0 and < 12.0-63.21≥ 12.1 and < 12.1-57.18≥ 13.0 and < 13.0-58.30 Vulnerable NIST National Vulnerability Database
Citrix Gateway Firmware ≥ 13.0 and < 13.0-58.30 Vulnerable NIST National Vulnerability Database
Citrix Netscaler Gateway Firmware ≥ 10.5 and < 10.5-70.18≥ 11.1 and < 11.1-64.14≥ 12.0 and < 12.0-63.21≥ 12.1 and < 12.1-57.18 Vulnerable NIST National Vulnerability Database
Citrix Sd-wan Wanop ≥ 10.2 and < 10.2.7≥ 11.0 and < 11.0.3d≥ 11.1 and < 11.1.1a Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.5 CVSS 3.1 Medium 3.9 2.5 nvd@nist.gov via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium 3.9 2.5 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
6.5 CVSS 3.1 Medium — — CISA-ADP via CVE Program (cve.org) e CISA ADP
5.0 CVSS 2.0 Medium 10.0 2.9 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-287 · Improper Authentication

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Nov 3, 2021
Federal deadline
May 3, 2022
passed 1626 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 88.41%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
  • Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Affected products added · citrix/application delivery controller firmware, citrix/netscaler gateway firmware, citrix/gateway firmware, citrix/sd-w
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 6.5
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2021
  • Added to CISA KEV catalog
    Nov 2, 2021 · CISA
  • 2020
  • CVE published
    Jul 10, 2020 · hackerone

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

Elsewhere on this site

Citrix
every CVE for this vendor
2021-11
what else CISA listed that month
Authentication
same class
CWE-287
other pages naming this weakness

Related CVEs (same products)

  • CVE-2022-27518 Citrix Application Delivery Controller (ADC) and Gateway Authentication Bypass Vulnerability KEV Dec 13, 2022
  • CVE-2020-8195 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Information Disclosure Vulnerability KEV Jul 10, 2020
  • CVE-2020-8196 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Information Disclosure Vulnerability KEV Jul 10, 2020
  • CVE-2019-19781 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Code Execution Vulnerability KEV Dec 27, 2019

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2020-8193 is "Citrix ADC, Gateway, and SD-WAN WANOP Appliance Authorization Bypass Vulnerability", rated Medium. It affects Application Delivery Controller Firmware (Citrix); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 6.5 describes technical severity. EPSS 88.41% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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