CVE-2025-63710: Simple Public Chat Room CSRF Vulnerability

CVE-2025-63710 Overview

CVE-2025-63710 is a Cross-Site Request Forgery (CSRF) vulnerability in the send_message.php endpoint of SourceCodester Simple Public Chat Room 1.0, developed by Pijey. The application does not implement CSRF protections such as anti-CSRF tokens, nonces, or SameSite cookie restrictions. An attacker can craft a malicious HTML page that, when loaded by an authenticated victim, silently issues a forged POST request to the vulnerable endpoint. The request executes with the victim's session privileges, allowing arbitrary messages to be posted in any chat room on the victim's behalf. The weakness is classified under CWE-352: Cross-Site Request Forgery.

Critical Impact
Authenticated users visiting an attacker-controlled page can be forced to send arbitrary chat messages without their knowledge or consent.

Affected Products

Pijey Simple Public Chat Room 1.0
SourceCodester Simple Public Chat Room (PHP project distribution)
Deployments exposing send_message.php without CSRF tokens

Discovery Timeline

2025-11-10 - CVE-2025-63710 published to the National Vulnerability Database
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2025-63710

Vulnerability Analysis

The send_message.php endpoint accepts state-changing POST requests without validating request origin. Because the application does not issue or check anti-CSRF tokens, any request bearing the victim's session cookie is treated as legitimate. Browsers automatically attach session cookies to cross-origin form submissions, so an off-site page can trigger authenticated actions. The exposure impacts integrity and confidentiality of chat data at limited scope, since attackers can only perform actions permitted to the authenticated user.

Root Cause

The root cause is missing origin validation on a state-changing HTTP endpoint. The developer did not implement any of the standard CSRF defenses: synchronizer tokens, double-submit cookies, custom request headers verified server-side, or SameSite=Lax/Strict session cookie attributes. send_message.php trusts the presence of the session cookie as sufficient proof of user intent.

Attack Vector

Exploitation requires an authenticated user to visit an attacker-controlled or attacker-influenced page while their chat room session is active. The attacker hosts an HTML document containing a hidden form targeting send_message.php with attacker-chosen parameters such as message and room_id. JavaScript automatically submits the form on page load. The victim's browser attaches the chat room session cookie, and the server processes the request as if the victim initiated it. No user interaction beyond page visit is required, and the attack succeeds silently without visible indicators. Refer to the CVE-2025-63710 research writeup for a proof-of-concept HTML payload demonstrating the auto-submitting form technique.

Detection Methods for CVE-2025-63710

Indicators of Compromise

POST requests to send_message.php with Referer or Origin headers pointing to domains outside the chat application
Chat messages posted by authenticated users containing content they deny sending
Unusual message submission patterns from a single session immediately after the user visited an external URL
Absence of anti-CSRF token parameters in submitted POST bodies

Detection Strategies

Inspect web server access logs for POST requests to send_message.php where the Referer header does not match the application's own hostname
Correlate user reports of unauthorized messages with proxy or WAF logs showing external referrers
Monitor for repeated identical POST payloads originating from different client IP addresses within short time windows

Monitoring Recommendations

Enable verbose HTTP logging on the chat application, capturing Referer, Origin, and User-Agent headers for all POST requests
Forward web server and application logs to a centralized analytics or SIEM platform for cross-referencing suspicious submissions
Alert on POST activity to send_message.php lacking valid CSRF token parameters once mitigations are deployed

How to Mitigate CVE-2025-63710

Immediate Actions Required

Restrict access to the chat application to trusted networks or authenticated internal users until a fix is in place
Set the session cookie SameSite attribute to Lax or Strict at the web server or PHP configuration level as a compensating control
Instruct users to log out of the chat application when not in use to shrink the exploitation window
Deploy a Web Application Firewall (WAF) rule that rejects POST requests to send_message.php when the Origin or Referer header is missing or off-domain

Patch Information

No official vendor patch has been published for Simple Public Chat Room 1.0 at the time of NVD publication. Administrators should implement CSRF tokens directly in the application source, validate the Origin and Referer headers on all state-changing endpoints, and enforce SameSite cookie attributes. Consult the SourceCodester project page for the base source code and the CVE research advisory for remediation guidance.

Workarounds

Add a per-session anti-CSRF token to every form and verify it server-side in send_message.php before processing the message
Validate the Origin header against an allowlist of trusted domains and reject mismatched requests with HTTP 403
Configure PHP session cookies with session.cookie_samesite=Strict and session.cookie_secure=1 in php.ini
Require a custom request header such as X-Requested-With: XMLHttpRequest for message submissions, since browsers block cross-origin custom headers by default

bash

# Configuration example: enforce SameSite and Secure cookies in php.ini
session.cookie_samesite = Strict
session.cookie_secure = 1
session.cookie_httponly = 1