CVE-2025-7114: Sim Sim Auth Bypass Vulnerability

CVE-2025-7114 Overview

CVE-2025-7114 is a missing authentication vulnerability in SimStudioAI sim affecting commits up to 37786d371e17d35e0764e1b5cd519d873d90d97b. The flaw resides in the POST function of apps/sim/app/api/files/upload/route.ts within the Session Handler component. An attacker can manipulate the Request argument to bypass authentication checks and interact with the file upload endpoint remotely. The exploit details have been publicly disclosed, and the vendor did not respond to early disclosure attempts. The vulnerability is tracked under [CWE-287] (Improper Authentication) and [CWE-434] (Unrestricted Upload of File with Dangerous Type).

Critical Impact
Remote attackers can reach a file upload endpoint without authentication, exposing the application to unauthorized file submission and potential follow-on attacks.

Affected Products

SimStudioAI sim up to commit 37786d371e17d35e0764e1b5cd519d873d90d97b
Component: Session Handler (apps/sim/app/api/files/upload/route.ts)
Function: POST handler in the file upload route

Discovery Timeline

2025-07-07 - CVE-2025-7114 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2025-7114

Vulnerability Analysis

The vulnerability stems from the absence of authentication checks in the POST handler defined in apps/sim/app/api/files/upload/route.ts. The Session Handler component fails to validate that the incoming Request originates from an authenticated session before processing the upload. Attackers can issue crafted HTTP requests directly to the upload route and have the server accept them as legitimate. Because the endpoint accepts file uploads, the missing authentication compounds with weak file-type controls, raising the risk of malicious file delivery into the application context. Public disclosure of the issue without a vendor response means defenders cannot rely on an upstream fix being available.

Root Cause

The root cause is improper authentication in the file upload route, mapped to [CWE-287]. The POST handler does not verify the session identity associated with the request before performing privileged operations. A secondary weakness, [CWE-434], applies because the unauthenticated endpoint handles file uploads, allowing attackers to push files into the application without any access control gate.

Attack Vector

The attack vector is network-based, with low complexity and no privileges or user interaction required. An attacker sends a crafted HTTP POST request to the /api/files/upload route. Because the handler skips authentication, the server processes the upload as if it came from a legitimate user. Public exploit details exist, increasing the likelihood of automated abuse.

No verified proof-of-concept code is available. See the GitHub Issue Report and VulDB entry #315025 for additional technical context.

Detection Methods for CVE-2025-7114

Indicators of Compromise

Unauthenticated POST requests to /api/files/upload reaching the application without a valid session cookie or bearer token.
Unexpected new files written to the upload storage location outside normal user workflows.
Spikes in request volume to the upload route from a single IP or a narrow set of IPs.

Detection Strategies

Inspect web server and application logs for POST requests to apps/sim/app/api/files/upload that lack session identifiers.
Correlate upload events with authentication events to identify uploads with no preceding login.
Apply file integrity monitoring on directories used by the upload handler to flag unauthorized writes.

Monitoring Recommendations

Enable verbose access logging on the upload route, capturing request headers, source IP, and authentication state.
Forward application and web proxy logs to a centralized analytics platform for retention and query.
Alert on uploads of executable, script, or archive file types arriving from unauthenticated sessions.

How to Mitigate CVE-2025-7114

Immediate Actions Required

Restrict network access to the sim application using firewall rules or a reverse proxy that enforces authentication before requests reach the upload endpoint.
Disable the /api/files/upload route at the reverse proxy until an authentication check is added to the handler.
Audit existing uploads for files written during periods when the endpoint was exposed.

Patch Information

No vendor patch is referenced in the available advisories. The vendor was contacted prior to disclosure and did not respond. Operators should track the GitHub Issue Report and the VulDB CTI #315025 entry for updates. Until an upstream fix lands, operators should apply the handler with a server-side session check that rejects requests lacking a validated session before any file processing occurs.

Workarounds

Place the application behind an authenticating reverse proxy that requires a valid session for /api/files/upload.
Add a middleware guard to the Next.js route that validates session state and returns 401 for unauthenticated callers.
Enforce strict file-type and size validation server-side to limit damage if an unauthenticated request slips through.
Rotate any credentials or tokens that may have been exposed through uploaded artifacts.

bash

# Example nginx guard requiring auth before reaching the upload route
location /api/files/upload {
    auth_request /auth/validate;
    proxy_pass http://sim_backend;
}

location = /auth/validate {
    internal;
    proxy_pass http://auth_service/validate;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
}