CVE-2021-36567Public exploitNetwork attack vector

Remote code execution via AbstractCache destructor gadget

Published Dec 6, 2021 · Updated Aug 4, 2024

Deserialization in ThinkPHP 6.0.8 allows remote attackers to execute system commands through attacker-controlled serialized input. The AbstractCache destructor saves attacker-set cache data through CacheStore, whose File driver invokes a controllable serialization callback such as system. Exploitation requires application code to pass remote-controlled data to PHP unserialize; the demonstration adds a POST route and writes a PHP file.

CVSS severity9.8
Critical
EPSS probability2.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Deserialization in ThinkPHP 6.0.8 allows remote attackers to execute system commands through attacker-controlled serialized input. The AbstractCache destructor saves attacker-set cache data through CacheStore, whose File driver invokes a controllable serialization callback such as system. Exploitation requires application code to pass remote-controlled data to PHP unserialize; the demonstration adds a POST route and writes a PHP file.

The record

CVE
CVE-2021-36567
Published
Dec 6, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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

10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NIST NVDCVSS: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.

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 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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