BuilderEngine 3.5.0 RCE via Unauthenticated Arbitrary File Upload

published 2025-07-10 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-21028

cvss: 9.3; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 3.9%; EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits: 1; Metasploit

An unrestricted file upload vulnerability exists in BuilderEngine 3.5.0 via the integration of the elFinder 2.0 file manager and its use of the jQuery File Upload plugin. The plugin fails to properly validate or restrict file types or locations during upload operations, allowing an attacker to upload a malicious .php file and subsequently execute arbitrary PHP code on the server under the context of the web server process. While the root vulnerability lies within the jQuery File Upload component, BuilderEngine’s improper integration and lack of access controls expose this functionality to unauthenticated users, resulting in full remote code execution.

Timeline

2016-09-18 First public exploit (Metasploit exploit/multi/http/builderengine_upload_exec)
2025-07-10 Published

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 15 mo ago (2025-07-11)

Exploit prediction

3.86% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Metasploit exploit/multi/http/builderengine_upload_exec BuilderEngine Arbitrary File Upload Vulnerability and execution metasploit exploit, excellent rank, 2016-09-18
raw.githubusercontent.com https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/multi/http/builderengine_upload_exec.rb referenced PoC, tagged "exploit" by a source, unverified
exploit-db.com https://www.exploit-db.com/exploits/40390 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.3	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
CNA	4.0	9.3	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

BuilderEngine CMS

Classification

Weakness

CWE-434 Unrestricted Upload of File with Dangerous Type
CWE-20 Improper Input Validation
CWE-306 Missing Authentication for Critical Functionality

References

raw.githubusercontent.com /rapid7/metasploit-framework/master/modules/exploits/multi/http/builderengine_upload_exec.rb
exploit
exploit-db.com /exploits/40390
exploit
support.alertlogic.com /hc/en-us/articles/115004703183-BuilderEngine-Content-Management-System-CMS-elFinder-2-0-Arbitrary-File-Upload
third-party-advisory
vulncheck.com /advisories/builder-engine-unauthenticated-arbitrary-file-upload
third-party-advisory

Sources

CVE List CVE-2025-34100
NVD CVE-2025-34100

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary