Unauthenticated PHP code execution via header backdoor
Published Jul 3, 2025 · Updated Jul 7, 2025
Code injection in PHPStudy 2016 through 2018 allows unauthenticated remote attackers to execute arbitrary PHP code. The l.php backdoor base64-decodes the Accept-Charset request header and evaluates the decoded payload without validation. A reachable affected web endpoint is sufficient; code runs as the web server user and can read, change, or delete data accessible to that account.
Summary
What happened
Code injection in PHPStudy 2016 through 2018 allows unauthenticated remote attackers to execute arbitrary PHP code. The l.php backdoor base64-decodes the Accept-Charset request header and evaluates the decoded payload without validation. A reachable affected web endpoint is sufficient; code runs as the web server user and can read, change, or delete data accessible to that account.
The record
- CVE
- CVE-2025-34061
- Published
- Jul 3, 2025
- Updated
- Jul 7, 2025
- Vendor
- Henan Xiaopi Security Technology
- Product
- PHPStudy
- Classifications
- CWE-94, CAPEC-242, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 3, 2025CVE publishedPublication date reported by the CVE source.
- Jul 7, 2025Record 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=2016 <=2018
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
- PHPStudy Backdoor Remote Code Execution Metasploit Modulefunctional · 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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