Skip to main content

Autoptimize CVE-2021-24376

CRITICAL
Unrestricted Upload of File with Dangerous Type (CWE-434)
2021-06-21 contact@wpscan.com
9.8
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V5 - File Handling File type validation, storage isolation
MITRE ATT&CK

2 techniques across 2 tactics: Command and Control, Persistence

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available.

Exploit ScenarioDerived

A remote attacker could upload malicious files that can be executed on the server by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.
No patch listed yet 3.7% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

The Autoptimize WordPress plugin before 2.7.8 attempts to delete malicious files (such as .php) form the uploaded archive via the "Import Settings" feature, after its extraction. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate file types server-side, store uploads outside webroot, use random filenames, scan for malware.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Unrestricted File Upload (CWE-434), which allows attackers to upload malicious files that can be executed on the server. The Autoptimize WordPress plugin before 2.7.8 attempts to delete malicious files (such as .php) form the uploaded archive via the "Import Settings" feature, after its extraction. However, the extracted folders are not checked and it is possible to upload a zip which contained a directory with PHP file in it and then it is not removed from the disk. It is a bypass of CVE-2020-24948 which allows sending a PHP file via the "Import Settings" functionality to achieve Remote Code Execution. Affected products include: Autoptimize. Version information: before 2.7.8.

Know when Autoptimize gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionNVD

The Autoptimize WordPress plugin before 2.7.8 attempts to delete malicious files (such as .php) form the uploaded archive via the "Import Settings" feature, after its extraction. However, the extracted folders are not checked and it is possible to upload a zip which contained a directory with PHP file in it and then it is not removed from the disk. It is a bypass of CVE-2020-24948 which allows sending a PHP file via the "Import Settings" functionality to achieve Remote Code Execution.

Threat Intelligence Overview

EPSS Score
3.7%
Top 11% exploitable
Exploit
POC
Public exploit code exists
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC Yes
EPSS 3.7%
Patch available No
Active threat No
Deciding rule
CRITICAL severity + public POC available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

73
Low Medium High Critical
KEV: 0
EPSS: +4
CVSS: +49
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Malicious file upload attacks exploit insufficient validation when web applications accept user-provided files.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)NVD

cpe:2.3:a:autoptimize:autoptimize:*:*:*:*:*:wordpress:*:*
CVE-2026-3220 HIGH POC
8.8 May 18

Unauthenticated stored cross-site scripting affects the Autoptimize (before 3.1.15), Clearfy Cache (before 2.4.2), and S

CVE-2021-24377 HIGH POC
8.1 Jun 21

The Autoptimize WordPress plugin before 2.7.8 attempts to remove potential malicious files from the extracted archive up

CVE-2020-24948 HIGH POC
7.2 Sep 03

The ao_ccss_import AJAX call in Autoptimize Wordpress Plugin 2.7.6 does not ensure that the file provided is a legitimat

CVE-2023-2113 MEDIUM POC
4.8 May 30

The Autoptimize WordPress plugin before 3.1.7 does not sanitise and escape the settings imported from a previous export,

CVE-2022-2635 MEDIUM POC
4.8 Sep 16

The Autoptimize WordPress plugin before 3.1.1 does not sanitise and escape some of its settings, which could allow high

CVE-2021-24378 MEDIUM POC
4.8 Jun 21

The Autoptimize WordPress plugin before 2.7.8 does not check for malicious files such as .html in the archive uploaded v

CVE-2021-24332 MEDIUM POC
4.8 May 24

The Autoptimize WordPress plugin before 2.8.4 was missing proper escaping and sanitisation in some of its settings, allo

CVE-2026-14995 HIGH
7.2 Oct 01

Stored cross-site scripting in the Autoptimize WordPress plugin (all versions up to and including 3.1.15.1) lets an unau

CVE-2026-2352 MEDIUM
6.4 Mar 20

A Stored Cross-Site Scripting (XSS) vulnerability exists in the Autoptimize WordPress plugin through version 3.1.14, cau

CVE-2026-2430 MEDIUM
6.4 Mar 20

The Autoptimize WordPress plugin contains a Stored Cross-Site Scripting (XSS) vulnerability in the lazy-loading image pr

CVE-2026-78471 MEDIUM
5.4 Oct 02

Stored cross-site scripting in the Autoptimize WordPress plugin (all versions up to and including 3.1.15.1) allows unaut

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy