CVE-2022-40889Public exploitNetwork attack vector

Unauthenticated code execution via unsafe object deserialization

Published Oct 18, 2022 · Updated May 13, 2025

Unsafe deserialization in PHPok 6.1 allows remote attackers to write a PHP web shell through a crafted call API request. The _format_ext_all path passes attacker-controlled, doubly URL-decoded data to unserialize(), while a weak alias comparison permits the route. No authentication is required, and successful exploitation writes attacker-controlled PHP into the cache directory for server-side execution.

CVSS severity9.8
Critical
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in PHPok 6.1 allows remote attackers to write a PHP web shell through a crafted call API request. The _format_ext_all path passes attacker-controlled, doubly URL-decoded data to unserialize(), while a weak alias comparison permits the route. No authentication is required, and successful exploitation writes attacker-controlled PHP into the cache directory for server-side execution.

The record

CVE
CVE-2022-40889
Published
Oct 18, 2022
Updated
May 13, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 18, 2022CVE publishedPublication date reported by the CVE source.
  2. May 13, 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?

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

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/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.

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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 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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