CVE-2025-8350: BiEticaret CMS Auth Bypass Vulnerability

CVE-2025-8350 Overview

CVE-2025-8350 is a critical vulnerability affecting Inrove Software and Internet Services BiEticaret CMS. The vulnerability combines Execution After Redirect (EAR) with Missing Authentication for Critical Function weaknesses, enabling attackers to bypass authentication mechanisms and perform HTTP Response Splitting attacks. This dual vulnerability chain allows unauthenticated remote attackers to gain unauthorized access to protected functionality and manipulate HTTP responses.

Critical Impact

Unauthenticated attackers can bypass authentication controls and manipulate HTTP responses, potentially gaining administrative access to e-commerce management systems and compromising customer data.

Affected Products

• BiEticaret CMS versions 2.1.13 through 19022026
• Inrove Software and Internet Services BiEticaret CMS installations

Discovery Timeline

• 2026-02-19 - CVE-2025-8350 published to NVD
• 2026-02-19 - Last updated in NVD database

Note: The vendor was contacted early about this disclosure but did not respond in any way.

Technical Details for CVE-2025-8350

Vulnerability Analysis

This vulnerability stems from the combination of two distinct weaknesses classified under CWE-306 (Missing Authentication for Critical Function). The Execution After Redirect (EAR) flaw occurs when the application continues processing requests after issuing a redirect response, allowing attackers to access protected functionality despite authentication checks appearing to redirect unauthorized users. Combined with missing authentication controls on critical functions, this creates a severe security gap where administrative operations can be performed without proper credential verification.

The HTTP Response Splitting component allows attackers to inject malicious headers into HTTP responses by inserting carriage return and line feed characters. This can be leveraged for cache poisoning, cross-site scripting, and session hijacking attacks against legitimate users of the CMS platform.

Root Cause

The root cause lies in improper implementation of authentication controls within BiEticaret CMS. The application fails to properly terminate request processing after sending redirect responses for unauthorized access attempts. Additionally, critical administrative functions lack proper authentication verification, allowing direct access to sensitive operations. The HTTP response handling also fails to properly sanitize user input before incorporating it into response headers.

Attack Vector

The vulnerability is exploitable remotely over the network without requiring any authentication or user interaction. An attacker can craft malicious HTTP requests that exploit the EAR condition by continuing to process requests after redirect responses. The authentication bypass allows direct access to administrative panels and functions that should require privileged access. HTTP Response Splitting can be achieved by injecting CRLF sequences into user-controlled input that is reflected in HTTP response headers.

Attack scenarios include:

• Direct access to administrative endpoints by ignoring redirect responses
• Session hijacking through injected Set-Cookie headers
• Cache poisoning to serve malicious content to other users
• Cross-site scripting via injected response body content

Detection Methods for CVE-2025-8350

Indicators of Compromise

• Unusual HTTP requests accessing administrative endpoints without valid session tokens
• HTTP responses containing unexpected or duplicate headers indicating response splitting attempts
• Access logs showing successful requests to protected resources from unauthenticated sources
• Evidence of CRLF sequences (%0d%0a or \r\n) in URL parameters or form inputs

Detection Strategies

• Monitor web application logs for requests to administrative endpoints that bypass normal authentication flows
• Implement web application firewall (WAF) rules to detect and block HTTP response splitting patterns
• Analyze HTTP response headers for anomalies such as duplicated headers or unexpected header injections
• Deploy intrusion detection signatures targeting EAR exploitation patterns

Monitoring Recommendations

• Enable detailed logging on BiEticaret CMS installations to capture authentication bypass attempts
• Configure alerting for access to critical functions from unauthenticated sessions
• Monitor for unusual patterns in HTTP response sizes that may indicate response splitting
• Review access patterns to administrative functions for anomalous behavior

How to Mitigate CVE-2025-8350

Immediate Actions Required

• Implement network-level access controls to restrict administrative interface access to trusted IP addresses
• Deploy a web application firewall with rules to detect authentication bypass and response splitting attempts
• Consider taking affected BiEticaret CMS instances offline until remediation is available
• Audit existing access logs for signs of exploitation

Patch Information

No vendor patch is currently available. According to the vulnerability disclosure, the vendor (Inrove Software and Internet Services) was contacted early about this disclosure but did not respond in any way. Organizations should monitor the USOM Security Notification TR-26-0077 for updates and alternative remediation guidance.

Workarounds

• Restrict access to administrative interfaces using IP allowlisting at the network or reverse proxy level
• Implement additional authentication layers such as VPN requirements for administrative access
• Deploy server-side input validation to sanitize CRLF characters from all user inputs
• Configure the web server to add proper response headers that prevent response splitting exploitation
• Consider migrating to an alternative CMS solution given the vendor's lack of response to security disclosures

# Example: Restrict admin access via nginx
location /admin {
    # Allow only trusted IP ranges
    allow 10.0.0.0/8;
    allow 192.168.1.0/24;
    deny all;
    
    # Additional security headers
    add_header X-Content-Type-Options nosniff;
    add_header X-Frame-Options DENY;
}