CVE-2022-27516Network attack vector

Unauthenticated brute-force protection bypass

Published Nov 8, 2022 · Updated May 1, 2025

Protection mechanism failure in Citrix ADC and Gateway allows remote attackers to bypass configured login-attempt limits. Citrix has not disclosed which login-processing locus incorrectly handles failed-attempt counting or enforcement. Exploitation requires a customer-managed Gateway or AAA virtual server with Max Login Attempts configured, enabling continued password guesses beyond the intended lockout threshold.

CVSS severity5.3
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Protection mechanism failure in Citrix ADC and Gateway allows remote attackers to bypass configured login-attempt limits. Citrix has not disclosed which login-processing locus incorrectly handles failed-attempt counting or enforcement. Exploitation requires a customer-managed Gateway or AAA virtual server with Max Login Attempts configured, enabling continued password guesses beyond the intended lockout threshold.

The record

CVE
CVE-2022-27516
Published
Nov 8, 2022
Updated
May 1, 2025
Vendor
Citrix
Product
Citrix ADC/Gateway
Classifications
CWE-693, CWE-307, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 8, 2022CVE publishedPublication date reported by the CVE source.
  2. May 1, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Citrix · Citrix ADC/Gatewayversion=0

Published CVSS scores

9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3Citrix Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
CWE-307Improper Restriction of Excessive Authentication Attempts
T1110Brute Force

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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