CVE-2025-34061

Severity CVSS v4.0:

CRITICAL

Type:

CWE-94 Code Injection

Publication date:

03/07/2025

Last modified:

15/04/2026

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.

Impact

Vector 4.0

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 CVSS v4.0 Severity and Metrics:

Base Score: 9.30 CRITICAL
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

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

9.30

Severity 4.0

CRITICAL

CVE-2025-34061

Description

Impact

References to Advisories, Solutions, and Tools