CVE-2025-11963 Overview
CVE-2025-11963 is a reflected cross-site scripting (XSS) vulnerability [CWE-79] in Saysis Computer Systems Trade Ltd. Co. StarCities. The flaw stems from improper neutralization of user input during web page generation. Attackers can craft malicious URLs that inject arbitrary script into the response returned to victims. Successful exploitation executes attacker-controlled JavaScript in the victim's browser session. The vulnerability affects all StarCities releases prior to version 1.1.61.
Critical Impact
Attackers can hijack authenticated sessions, steal credentials, and perform actions on behalf of victims through crafted links that require user interaction.
Affected Products
- Saysis StarCities versions prior to 1.1.61
Discovery Timeline
- 2025-11-19 - CVE-2025-11963 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-11963
Vulnerability Analysis
The vulnerability is a reflected XSS flaw in the StarCities web application. Reflected XSS occurs when a server includes unsanitized user-supplied input directly in an HTTP response. When a victim clicks a crafted link, the injected script executes in the context of the vulnerable origin.
Exploitation requires user interaction and low-privileged access to the application. The scope is changed, meaning the vulnerability can affect resources beyond the vulnerable component, typically the victim's browser session and other origins the user trusts.
Because the payload runs in the victim's browser, attackers can access session cookies not protected by HttpOnly, read Document Object Model (DOM) content, submit forms, and pivot to other application functions. Public exploit code is not currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Root Cause
StarCities fails to properly encode or sanitize input before reflecting it in generated web pages. Any parameter that returns user input into the HTML response without contextual output encoding is a candidate injection point. The application does not enforce a strict Content Security Policy (CSP) capable of blocking inline script execution.
Attack Vector
An attacker crafts a URL to a vulnerable StarCities endpoint containing a JavaScript payload in a reflected parameter. The attacker delivers the link through phishing email, chat, or an attacker-controlled site. When an authenticated user opens the link, the browser executes the payload under the StarCities origin.
No verified proof-of-concept code is publicly available. Refer to the USOM Notification TR-25-0403 and Siber Güvenlik Notification TR-25-0403 for vendor-coordinated advisory details.
Detection Methods for CVE-2025-11963
Indicators of Compromise
- HTTP request logs containing URL parameters with encoded script fragments such as %3Cscript%3E, javascript:, onerror=, or onload= targeting StarCities endpoints.
- Unexpected outbound requests from user browsers to attacker-controlled domains following a StarCities session.
- Session cookie theft indicators, including logins from anomalous IPs shortly after a user clicks a suspicious link.
Detection Strategies
- Deploy a Web Application Firewall (WAF) rule set that flags reflected script tags and event-handler attributes in query strings and POST bodies.
- Correlate web server access logs with user-agent and referrer anomalies to surface phishing-delivered XSS attempts.
- Enable browser Content Security Policy violation reporting and forward reports to a centralized logging platform for review.
Monitoring Recommendations
- Ingest StarCities web server and reverse proxy logs into a centralized SIEM for query-string analysis.
- Alert on repeated 4xx or 5xx responses containing script metacharacters in request parameters.
- Track authentication events for cookie reuse from unexpected geolocations following user link clicks.
How to Mitigate CVE-2025-11963
Immediate Actions Required
- Upgrade StarCities to version 1.1.61 or later, which contains the vendor fix.
- Inventory all StarCities deployments and confirm current version through vendor console or package metadata.
- Rotate session tokens and force reauthentication after patching to invalidate any hijacked sessions.
Patch Information
Saysis Computer Systems Trade Ltd. Co. addressed the vulnerability in StarCities 1.1.61. Administrators should apply the update through the vendor's standard release channel. Coordinate patch validation with the advisories published by USOM and Siber Güvenlik.
Workarounds
- Deploy a WAF rule that blocks requests containing <script>, javascript:, and common event handlers in query parameters until patching completes.
- Enforce a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.
- Set the HttpOnly and Secure flags on session cookies to limit script-based cookie theft.
- Train users to avoid clicking unverified links pointing to StarCities application URLs.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
