CVE-2021-36169

Privileged code execution via arbitrary memory writes

Published Dec 13, 2021 · Updated Oct 25, 2024

Hidden debug functionality in Fortinet FortiOS 7.0.0, 6.4.6, and 6.2.9 allows local users to execute unauthorized code or commands. The CLI chains print str and cmd mem debug commands to read hexadecimal values from, or write them to, any memory address. Exploitation requires a highly privileged local session; arbitrary reads expose memory, while writes enable code or command execution.

CVSS severity4.2
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hidden debug functionality in Fortinet FortiOS 7.0.0, 6.4.6, and 6.2.9 allows local users to execute unauthorized code or commands. The CLI chains print str and cmd mem debug commands to read hexadecimal values from, or write them to, any memory address. Exploitation requires a highly privileged local session; arbitrary reads expose memory, while writes enable code or command execution.

The record

CVE
CVE-2021-36169
Published
Dec 13, 2021
Updated
Oct 25, 2024
Vendor
Fortinet
Product
FortiOS
Classifications
T1059
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 13, 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=FortiOS 7.0.0, 6.4.6, 6.2.9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Fortinet · FortiOSversion=FortiOS 7.0.0, 6.4.6, 6.2.9

Published CVSS scores

4.2FortinetCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
6.0NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
6.6NVDAV:L/AC:L/Au:N/C:C/I:C/A:N
4.0FortinetCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:C

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1059Command and Scripting Interpreter

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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