CVE-2021-24280Network attack vector

Authenticated PHP object injection via unsafe unserialize

Published May 14, 2021 · Updated Aug 3, 2024

PHP object injection in Redirection for Contact Form 7 before 2.3.4 allows remote authenticated users to instantiate attacker-selected objects. The import_from_debug AJAX handler base64-decodes the submitted debug_info value and passes it directly to PHP unserialize without restricting permitted classes. Subscriber-level access reaches the action; code execution or arbitrary file creation additionally requires a suitable magic-method gadget in the site’s loaded PHP classes.

CVSS severity7.5
High
EPSS probability1.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

PHP object injection in Redirection for Contact Form 7 before 2.3.4 allows remote authenticated users to instantiate attacker-selected objects. The import_from_debug AJAX handler base64-decodes the submitted debug_info value and passes it directly to PHP unserialize without restricting permitted classes. Subscriber-level access reaches the action; code execution or arbitrary file creation additionally requires a suitable magic-method gadget in the site’s loaded PHP classes.

The record

CVE
CVE-2021-24280
Published
May 14, 2021
Updated
Aug 3, 2024
Vendor
Query Solutions Ltd.
Product
Redirection for Contact Form 7
Classifications
CWE-502, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 14, 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=2.3.4 <2.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Query Solutions Ltd. · Redirection for Contact Form 7version=2.3.4 <2.3.4

Published CVSS scores

7.5WordfenceCVSS:3.1/AV:N/AC:H/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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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