Unauthenticated code execution via unrestricted PHP file creation
Published Oct 16, 2024 · Updated Apr 8, 2026
Arbitrary file creation in QuadLayers QuadMenu 2.0.6 and earlier allows remote attackers to execute PHP code through an AJAX request. The unauthenticated quadmenu_compiler_save action accepts an attacker-chosen import filename and CSS content, exposes its nonce on the public homepage, and writes the content under WordPress uploads without restricting the .php extension. No account or user interaction is required; successful exploitation creates a web-accessible PHP file and yields code execution in the WordPress server context.
Summary
What happened
Arbitrary file creation in QuadLayers QuadMenu 2.0.6 and earlier allows remote attackers to execute PHP code through an AJAX request. The unauthenticated quadmenu_compiler_save action accepts an attacker-chosen import filename and CSS content, exposes its nonce on the public homepage, and writes the content under WordPress uploads without restricting the .php extension. No account or user interaction is required; successful exploitation creates a web-accessible PHP file and yields code execution in the WordPress server context.
The record
- CVE
- CVE-2021-4443
- Published
- Oct 16, 2024
- Updated
- Apr 8, 2026
- Vendor
- Roman Pronskiy
- Product
- QuadMenu
- Classifications
- CWE-434, T1505.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 16, 2024CVE publishedPublication date reported by the CVE source.
- Apr 8, 2026Record 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.
- Affected versionversion=0 <=2.0.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- QuadMenu compiler_save proof of conceptfunctional · demonstrated
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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