Unauthenticated arbitrary file upload via extension blacklist
Published Dec 20, 2023 · Updated Apr 28, 2026
Unrestricted file upload in Plugin Planet User Submitted Posts 20230902 and earlier allows remote attackers to upload dangerous files. The usp_attach_images function rejects names containing php but lacks an allowlist, so alternate executable extensions such as phtml pass validation. No account is required; code execution follows when the web server treats the uploaded extension as executable content.
Summary
What happened
Unrestricted file upload in Plugin Planet User Submitted Posts 20230902 and earlier allows remote attackers to upload dangerous files. The usp_attach_images function rejects names containing php but lacks an allowlist, so alternate executable extensions such as phtml pass validation. No account is required; code execution follows when the web server treats the uploaded extension as executable content.
The record
- CVE
- CVE-2023-45603
- Published
- Dec 20, 2023
- Updated
- Apr 28, 2026
- Vendor
- Plugin Planet
- Product
- User Submitted Posts
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 20, 2023CVE publishedPublication date reported by the CVE source.
- Apr 28, 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=n/a <=20230902 changes=[{"at":"20230914","status":"unaffected"}]
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
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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