CVE-2026-9603: eDoc Appointment System Auth Bypass Flaw

CVE-2026-9603 Overview

CVE-2026-9603 is a missing authorization vulnerability [CWE-862] in SourceCodester eDoc Doctor Appointment System 1.0. The flaw resides in the /admin/delete-session.php script, where the ID parameter can be manipulated by remote attackers without proper authorization checks. Exploitation requires no authentication and no user interaction. A public proof-of-concept has been disclosed, increasing the likelihood of opportunistic abuse against exposed instances. The vulnerability allows attackers to invoke administrative delete operations and remove session records, impacting integrity and availability of the application data.

Critical Impact

Remote unauthenticated attackers can delete session records through the admin endpoint, undermining application integrity and availability.

Affected Products

• SourceCodester eDoc Doctor Appointment System 1.0
• Component: /admin/delete-session.php
• Affected parameter: ID

Discovery Timeline

• 2026-05-26 - CVE-2026-9603 published to the National Vulnerability Database (NVD)
• 2026-05-27 - Last updated in NVD database

Technical Details for CVE-2026-9603

Vulnerability Analysis

The vulnerability stems from a missing authorization check in the administrative delete-session handler. The /admin/delete-session.php script processes the ID argument and performs a delete operation without validating whether the requester holds an authenticated administrative session. Because the endpoint is reachable over the network and accepts attacker-supplied identifiers, any remote actor can issue crafted requests to remove arbitrary session records.

The weakness is classified as [CWE-862] Missing Authorization. Exploitation does not require credentials, privileges, or user interaction, and the public proof-of-concept lowers the barrier for opportunistic attacks. Successful exploitation does not yield code execution, but it does enable unauthorized data modification within the application's session store.

Root Cause

The handler fails to enforce server-side access control before executing database delete operations. Authorization logic is either absent or relies on client-side assumptions, allowing direct invocation of the script from unauthenticated contexts. This is a common pattern in PHP applications that place authentication checks only on UI entry points rather than on every server-side action.

Attack Vector

An attacker sends an HTTP request to /admin/delete-session.php with a chosen ID value targeting an existing session record. Because the endpoint does not validate session ownership or role, the record is deleted. The attack vector is network-based and can be automated against any exposed deployment. Refer to the GitHub Security Advisory and the GitHub PoC Script for technical details.

Detection Methods for CVE-2026-9603

Indicators of Compromise

• Unexpected HTTP requests to /admin/delete-session.php originating from unauthenticated clients or unknown source IP addresses.
• Sudden deletions of session rows in the application database without corresponding administrative login events.
• Web server access logs showing repeated GET or POST requests to the admin endpoint with varying ID parameter values.

Detection Strategies

• Correlate requests to /admin/delete-session.php against authenticated admin session tokens; flag requests lacking a valid session cookie.
• Deploy web application firewall (WAF) rules that require an authenticated session cookie for any URI under /admin/.
• Monitor database audit logs for DELETE statements against the session table outside expected administrative workflows.

Monitoring Recommendations

• Enable verbose HTTP access logging on the web server hosting eDoc Doctor Appointment System.
• Alert on access to /admin/* endpoints from IPs outside trusted administrative ranges.
• Capture and retain request bodies and parameters for forensic review of the ID argument values used.

How to Mitigate CVE-2026-9603

Immediate Actions Required

• Restrict network access to the /admin/ directory using IP allowlists or VPN gating until a vendor patch is available.
• Add a server-side authorization check at the top of delete-session.php that verifies an authenticated administrator session before processing.
• Review the session table for unexpected deletions and restore from backups where necessary.

Patch Information

No official vendor patch has been published at the time of NVD disclosure. Monitor the SourceCodester project page and the VulDB entry #365676 for vendor updates. In the interim, apply source-level fixes to enforce role-based access control on all administrative scripts.

Workarounds

• Place the application behind an authenticating reverse proxy that blocks unauthenticated requests to /admin/ paths.
• Add a WAF rule to deny requests to /admin/delete-session.php unless they include a valid administrative session cookie and a CSRF token.
• Audit all other scripts under /admin/ for the same missing authorization pattern and apply consistent access checks.

# Example Apache .htaccess restriction for /admin directory
<Directory "/var/www/html/admin">
    Require ip 10.0.0.0/8
    Require ip 192.168.0.0/16
</Directory>