CVE-2021-24307Public exploitNetwork attack vector

Authenticated host command execution via INI deserialization

Published May 24, 2021 · Updated Aug 3, 2024

Deserialization in AIOSEO Plugin Team All in One SEO before 4.1.0.2 allows remote authenticated users to execute host commands. The Import/Export REST handler unserializes uploaded INI values, letting bundled Monolog classes form a command-execution gadget chain. Access requires the aioseo_tools_settings privilege, normally held by administrators, and commands run with the PHP host process privileges.

CVSS severity8.8
High
EPSS probability53.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in AIOSEO Plugin Team All in One SEO before 4.1.0.2 allows remote authenticated users to execute host commands. The Import/Export REST handler unserializes uploaded INI values, letting bundled Monolog classes form a command-execution gadget chain. Access requires the aioseo_tools_settings privilege, normally held by administrators, and commands run with the PHP host process privileges.

The record

CVE
CVE-2021-24307
Published
May 24, 2021
Updated
Aug 3, 2024
Vendor
AIOSEO Plugin Team
Product
All in One SEO
Classifications
CWE-502, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=4.1.0.2 <4.1.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

AIOSEO Plugin Team · All in One SEOversion=4.1.0.2 <4.1.0.2

Published CVSS scores

9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

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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