Unauthenticated code execution via filename-length bypass
Published Nov 16, 2024 · Updated Apr 8, 2026
Arbitrary file upload in Revmakx Backup and Staging by WP Time Capsule 1.22.21 and earlier allows remote attackers to execute PHP code. UploadHandler.php treats a failed strrpos extension search as position zero, so any three-, four-, or six-character filename can pass the suffix allowlist. Exploitation requires the upload index.php file created when an administrator displays upload options; a successful request writes and exposes attacker-controlled PHP.
Summary
What happened
Arbitrary file upload in Revmakx Backup and Staging by WP Time Capsule 1.22.21 and earlier allows remote attackers to execute PHP code. UploadHandler.php treats a failed strrpos extension search as position zero, so any three-, four-, or six-character filename can pass the suffix allowlist. Exploitation requires the upload index.php file created when an administrator displays upload options; a successful request writes and exposes attacker-controlled PHP.
The record
- CVE
- CVE-2024-8856
- Published
- Nov 16, 2024
- Updated
- Apr 8, 2026
- Vendor
- Revmakx
- Product
- Backup and Staging by WP Time Capsule
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 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 <=1.22.21
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
- Researcher HTTP proof of conceptproof of concept · demonstrated
- Metasploit WP Time Capsule file upload RCE moduleweaponized · validated
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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