CVE-2021-22124Network attack vector

Unauthenticated service interruption via oversized login parameters

Published Aug 4, 2021 · Updated Oct 25, 2024

Uncontrolled resource consumption in FortiSandbox and FortiAuthenticator login modules allows remote attackers to make devices unresponsive. The login modules process specifically crafted long request parameters until resources are exhausted; Fortinet has not disclosed a narrower code-level locus. Unauthenticated network access to a login interface is sufficient, and successful exploitation interrupts the appliance until responsiveness is restored.

CVSS severity7.5
High
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in FortiSandbox and FortiAuthenticator login modules allows remote attackers to make devices unresponsive. The login modules process specifically crafted long request parameters until resources are exhausted; Fortinet has not disclosed a narrower code-level locus. Unauthenticated network access to a login interface is sufficient, and successful exploitation interrupts the appliance until responsiveness is restored.

The record

CVE
CVE-2021-22124
Published
Aug 4, 2021
Updated
Oct 25, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:C
7.5Fortinet, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

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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