CVE-2021-36174Network attack vector

Service interruption via excessive license-blob memory allocation

Published Nov 2, 2021 · Updated Oct 25, 2024

Uncontrolled memory allocation in Fortinet FortiPortal before 6.0.6 allows remote attackers to interrupt service via crafted license blobs. The license verification function uses an excessive allocation size derived from attacker-controlled blob data, exhausting memory during verification. The attack is unauthenticated but requires user interaction, and the reported consequence is limited to service availability.

CVSS severity7.5
High
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled memory allocation in Fortinet FortiPortal before 6.0.6 allows remote attackers to interrupt service via crafted license blobs. The license verification function uses an excessive allocation size derived from attacker-controlled blob data, exhausting memory during verification. The attack is unauthenticated but requires user interaction, and the reported consequence is limited to service availability.

The record

CVE
CVE-2021-36174
Published
Nov 2, 2021
Updated
Oct 25, 2024
Vendor
Fortinet
Product
FortiPortal
Classifications
CWE-789, CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 2, 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?

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

  1. Affected versionversion=FortiPortal before 6.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fortinet · FortiPortalversion=FortiPortal before 6.0.6

Published CVSS scores

4.3FortinetCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

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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