CVE-2025-7840 Overview
CVE-2025-7840 is a cross-site scripting (XSS) vulnerability [CWE-79] affecting Campcodes Online Movie Theater Seat Reservation System version 1.0. The flaw resides in the /index.php?page=reserve endpoint, part of the Reserve Your Seat Page component. Attackers can inject malicious script payloads through the Firstname and Lastname parameters. The application fails to sanitize these inputs before rendering them in the response. Exploitation occurs remotely over the network and requires user interaction. The exploit has been disclosed publicly, increasing the likelihood of opportunistic abuse against exposed installations.
Critical Impact
Attackers can execute arbitrary JavaScript in the browser context of users viewing the Reserve Your Seat Page, enabling session hijacking, credential theft, and defacement.
Affected Products
- Campcodes Online Movie Theater Seat Reservation System 1.0
- Reserve Your Seat Page component (/index.php?page=reserve)
- Deployments exposing Firstname and Lastname input fields
Discovery Timeline
- 2025-07-19 - CVE-2025-7840 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-7840
Vulnerability Analysis
The vulnerability is a stored or reflected cross-site scripting flaw in the reservation workflow of the Campcodes Online Movie Theater Seat Reservation System. The Firstname and Lastname parameters submitted to /index.php?page=reserve are echoed back to the browser without proper HTML encoding or input filtering. An attacker who submits crafted values containing script tags or event handlers can cause the payload to execute in the victim's session.
Successful exploitation can be used to steal session cookies, capture form data, perform actions on behalf of authenticated users, or redirect victims to attacker-controlled infrastructure. Because the vulnerable endpoint is part of a customer-facing reservation flow, the payload may execute in the context of both end users and administrators who review reservation data.
Root Cause
The root cause is missing output encoding and improper input validation on the Firstname and Lastname parameters within the Reserve Your Seat Page. User-supplied data flows directly into the HTML response without invoking a context-aware encoder or applying an allowlist filter. This aligns with the classic [CWE-79] pattern of neutralizing input during web page generation.
Attack Vector
Exploitation requires network access to the vulnerable web application and a low-privileged user account, plus interaction from a victim. An attacker submits a reservation containing a malicious payload in the Firstname or Lastname field. When any user, including administrators processing reservations, loads a page that renders the value, the injected JavaScript executes in their browser. Full technical discussion is available in the GitHub CVE Issue Discussion and VulDB CVE Details.
No verified proof-of-concept code was published in a controlled repository at the time of writing. Refer to the linked advisory for reproduction steps.
Detection Methods for CVE-2025-7840
Indicators of Compromise
- HTTP POST or GET requests to /index.php?page=reserve containing <script>, onerror=, onload=, or javascript: sequences in Firstname or Lastname parameters.
- Reservation records in the backend database with HTML or JavaScript syntax inside customer name fields.
- Unexpected outbound requests from administrator browsers to unfamiliar domains after viewing reservation lists.
Detection Strategies
- Deploy web application firewall (WAF) rules that inspect the Firstname and Lastname parameters for common XSS payload patterns.
- Enable server-side request logging on the reservation endpoint and alert on payloads containing angle brackets or event handler keywords.
- Perform periodic database audits to identify stored reservation entries containing markup or script content.
Monitoring Recommendations
- Monitor administrator sessions for anomalous cookie access, token exfiltration, or unexpected navigation triggered while reviewing reservations.
- Log and review Content Security Policy (CSP) violation reports if CSP is deployed on the application.
- Correlate WAF blocks against reservation traffic to identify probing attempts before successful storage of a payload.
How to Mitigate CVE-2025-7840
Immediate Actions Required
- Restrict public access to /index.php?page=reserve while a fix is evaluated, using network access controls or authentication gates.
- Deploy WAF signatures that block XSS payloads targeting the Firstname and Lastname parameters.
- Sanitize existing reservation records in the database to remove any stored HTML or JavaScript content.
Patch Information
No vendor patch is referenced in the NVD entry for CVE-2025-7840. Consult the CampCodes Security Blog and the VulDB Submission Details for updates on remediation availability. Until an official update is released, operators should apply compensating controls and consider retiring the affected application version from production.
Workarounds
- Implement context-aware output encoding on all values rendered from the reservation table, using an HTML encoder for name fields.
- Apply strict server-side input validation, allowing only alphabetic characters, spaces, hyphens, and apostrophes in Firstname and Lastname inputs.
- Enforce a restrictive Content Security Policy that disables inline scripts and blocks execution of untrusted script sources.
- Set the HttpOnly and Secure flags on session cookies to reduce the impact of successful script execution.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
