CVE-2023-23857 Overview
CVE-2023-23857 is an authentication bypass vulnerability in SAP NetWeaver Application Server for Java version 7.50. Due to a missing authentication check, an unauthenticated attacker can attach to an open interface and make use of an open naming and directory API to access services. This vulnerability can be used to perform unauthorized operations affecting users and services across systems.
Critical Impact
Successful exploitation allows attackers to read and modify sensitive information, and can be used to lock up any element or operation of the system, making it unresponsive or unavailable.
Affected Products
- SAP NetWeaver Application Server for Java version 7.50
Discovery Timeline
- March 14, 2023 - CVE-2023-23857 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2023-23857
Vulnerability Analysis
This vulnerability stems from a missing authentication check (CWE-287) in SAP NetWeaver Application Server for Java. The flaw allows unauthenticated attackers to connect to exposed interfaces and leverage the naming and directory API without proper authorization verification. Once connected, attackers can access internal services and perform operations that should require authentication.
The impact is threefold: confidentiality is compromised as attackers can read sensitive information, integrity is affected as modification of data is possible, and availability is severely impacted as attackers can lock system elements rendering them unresponsive.
Root Cause
The root cause of CVE-2023-23857 is a missing authentication check in the naming and directory API interface. The API endpoint fails to verify whether incoming requests originate from authenticated users before processing them, allowing unauthenticated access to privileged functionality.
Attack Vector
The attack vector is network-based, requiring no user interaction or prior authentication. An attacker can remotely connect to the exposed interface and leverage the open naming and directory API. The attack complexity is low as no special conditions are required beyond network access to the vulnerable endpoint.
The exploitation flow involves:
- Identifying an exposed SAP NetWeaver AS for Java instance running version 7.50
- Connecting to the open naming and directory API interface
- Leveraging the API to enumerate and access internal services
- Performing unauthorized operations such as reading sensitive data, modifying information, or locking system components to cause denial of service
Detection Methods for CVE-2023-23857
Indicators of Compromise
- Unexpected connections to naming and directory API endpoints from untrusted sources
- Unusual API calls or service access patterns from unauthenticated sessions
- System lockups or unresponsive elements without legitimate administrative action
- Unauthorized data access or modification in SAP NetWeaver logs
Detection Strategies
- Monitor network traffic for unauthenticated connections to SAP NetWeaver AS for Java interfaces
- Implement logging for all naming and directory API access attempts
- Configure alerts for service access from sessions without valid authentication tokens
- Review SAP security audit logs for anomalous patterns indicating unauthorized operations
Monitoring Recommendations
- Enable detailed logging on SAP NetWeaver Application Server for Java instances
- Deploy network intrusion detection systems (NIDS) to monitor traffic to SAP endpoints
- Establish baseline behavior for API access patterns and alert on deviations
- Regularly audit access logs for signs of reconnaissance or exploitation attempts
How to Mitigate CVE-2023-23857
Immediate Actions Required
- Apply the security patch from SAP as documented in SAP Note #3252433
- Restrict network access to SAP NetWeaver AS for Java interfaces using firewalls
- Review and limit exposure of naming and directory API endpoints
- Monitor systems for signs of exploitation until patches are applied
Patch Information
SAP has released a security patch addressing this vulnerability. Organizations should consult SAP Note #3252433 for detailed patching instructions. Additional security guidance is available in the SAP Security Document Overview.
Workarounds
- Implement network segmentation to isolate SAP NetWeaver AS for Java instances from untrusted networks
- Configure firewall rules to restrict access to the naming and directory API to trusted IP addresses only
- Disable or restrict the vulnerable interface if not required for business operations
- Deploy a web application firewall (WAF) to filter malicious requests targeting the vulnerable endpoint
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
