CVE-2024-4358: Telerik Report Server Auth Bypass Flaw

CVE-2024-4358 Overview

CVE-2024-4358 is a critical authentication bypass vulnerability affecting Progress Telerik Report Server version 2024 Q1 (10.0.24.305) and earlier when deployed on Internet Information Services (IIS). This vulnerability allows unauthenticated attackers to gain access to restricted functionality within Telerik Report Server by bypassing authentication mechanisms.

The vulnerability is classified under CWE-290 (Authentication Bypass by Spoofing), indicating that the flaw allows attackers to circumvent authentication controls through spoofing techniques. Given that Telerik Report Server is widely used in enterprise environments for business intelligence and reporting, this vulnerability poses significant risk to organizations relying on this software.

Critical Impact

This vulnerability is actively exploited in the wild and has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog. Unauthenticated attackers can bypass authentication to access restricted server functionality, potentially leading to unauthorized data access and system compromise.

Affected Products

• Progress Telerik Report Server 2024 Q1 (10.0.24.305) and earlier versions
• Telerik Report Server deployments on IIS
• All versions prior to the security patch release

Discovery Timeline

• 2024-05-29 - CVE-2024-4358 published to NVD
• 2025-10-31 - Last updated in NVD database

Technical Details for CVE-2024-4358

Vulnerability Analysis

This authentication bypass vulnerability exists in the registration mechanism of Progress Telerik Report Server. The flaw enables unauthenticated remote attackers to gain unauthorized access to restricted functionality without providing valid credentials. The vulnerability specifically affects deployments running on Microsoft IIS web server infrastructure.

The attack can be executed remotely over the network without requiring any user interaction or prior authentication. When successfully exploited, attackers can achieve complete compromise of confidentiality, integrity, and availability of the affected system. This makes the vulnerability particularly dangerous for internet-facing Telerik Report Server installations.

Root Cause

The root cause of CVE-2024-4358 lies in improper authentication validation within the Telerik Report Server registration process. The application fails to properly verify authentication credentials in certain request scenarios, allowing attackers to spoof authentication and gain access to protected functionality. This is a classic CWE-290 vulnerability where authentication bypass occurs through request manipulation or spoofing techniques.

Attack Vector

The attack vector for CVE-2024-4358 is network-based, requiring the attacker to have network access to the vulnerable Telerik Report Server instance. The attack does not require any privileges or user interaction, making it highly exploitable. Attackers can craft malicious requests that bypass the authentication mechanism, allowing them to access restricted areas of the Report Server that would normally require valid credentials.

The vulnerability is particularly concerning because exploit code is publicly available through ExploitDB, significantly lowering the barrier to exploitation. Organizations with internet-exposed Telerik Report Server installations are at heightened risk.

Detection Methods for CVE-2024-4358

Indicators of Compromise

• Unexpected user account creation or registration activity in Telerik Report Server logs
• Authentication logs showing access to restricted functionality without corresponding successful login events
• Anomalous HTTP requests targeting Telerik Report Server registration or authentication endpoints
• Unauthorized access to reports or server configuration from unknown IP addresses

Detection Strategies

• Monitor IIS access logs for unusual patterns targeting Telerik Report Server authentication endpoints
• Implement web application firewall (WAF) rules to detect and block authentication bypass attempts
• Deploy network intrusion detection signatures for known CVE-2024-4358 exploitation patterns
• Review Telerik Report Server audit logs for unauthorized access or privilege escalation events

Monitoring Recommendations

• Enable verbose logging on Telerik Report Server and IIS for forensic analysis capabilities
• Configure SIEM alerts for failed authentication attempts followed by successful access to restricted areas
• Monitor for exploitation attempts using threat intelligence feeds that track CVE-2024-4358 activity
• Implement behavioral analysis to detect anomalous access patterns to reporting functionality

How to Mitigate CVE-2024-4358

Immediate Actions Required

• Update Progress Telerik Report Server to the latest patched version immediately
• Review server logs for signs of compromise or unauthorized access prior to patching
• Restrict network access to Telerik Report Server instances, limiting exposure to trusted networks only
• Implement additional authentication controls such as VPN or network segmentation for Report Server access

Patch Information

Progress has released a security patch to address this vulnerability. Organizations should consult the Telerik Knowledge Base Advisory for detailed patching instructions and download links. Given the critical severity and active exploitation status, patching should be treated as an emergency priority.

This vulnerability has been added to the CISA Known Exploited Vulnerabilities catalog, which mandates federal agencies to remediate within specified timeframes. Private organizations should follow similar urgency in their remediation efforts.

Workarounds

• Implement network-level access controls to restrict access to Telerik Report Server from trusted IP ranges only
• Place the Telerik Report Server behind a reverse proxy with strong authentication requirements
• Disable or restrict the registration functionality if not required for business operations
• Deploy web application firewall rules to filter malicious authentication bypass requests

# IIS URL Rewrite rule example to restrict access to registration endpoints
# Add to web.config in Telerik Report Server root directory
# Note: This is a temporary workaround - apply official patch as soon as possible

# Restrict registration endpoint access
netsh advfirewall firewall add rule name="Restrict Telerik Report Server" dir=in action=allow protocol=tcp localport=83 remoteip=10.0.0.0/8,172.16.0.0/12,192.168.0.0/16