CVE-2023-23860 in NetWeaver Application Server ABAP
Summary
by MITRE • 02/14/2023
SAP NetWeaver AS for ABAP and ABAP Platform - versions 740, 750, 751, 752, 753, 754, 755, 756, 757, 789, 790, allows an unauthenticated attacker to craft a link, which when clicked by an unsuspecting user can be used to redirect a user to a malicious site which could read or modify some sensitive information or expose the victim to a phishing attack.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/14/2023
This vulnerability exists in SAP NetWeaver AS for ABAP and ABAP Platform across multiple versions including 740 through 790, representing a critical security flaw that enables server-side request forgery attacks. The vulnerability stems from inadequate input validation and sanitization mechanisms within the application's URL handling functionality, allowing attackers to construct malicious links that can be used to redirect users to attacker-controlled domains. The flaw specifically affects the application's ability to properly validate and sanitize external references, creating an attack vector that can be exploited through crafted web requests.
The technical implementation of this vulnerability allows an unauthenticated attacker to craft specially formatted links that, when clicked by an unsuspecting user, will redirect the victim to a malicious domain. This redirection can occur without any user authentication requirements, making the attack surface particularly dangerous as it can target any user with access to the vulnerable system. The vulnerability operates by manipulating the application's URL parsing and redirection mechanisms, bypassing normal security controls that should validate external references before allowing redirection to external domains.
From an operational impact perspective, this vulnerability creates significant risks for organizations using affected SAP systems, as it enables sophisticated phishing campaigns and data exfiltration attempts. The attack can result in unauthorized access to sensitive information, credential theft, and potential lateral movement within the network. Users who click on malicious links may unknowingly provide credentials to attackers or have sensitive data read from their sessions. The vulnerability also enables man-in-the-middle attacks where attackers can intercept communications and manipulate data flows between users and the SAP system.
The security implications extend beyond simple redirection attacks, as this vulnerability can be leveraged as a stepping stone for more complex attacks. According to the CWE taxonomy, this represents a weakness in the system's input validation and output encoding processes, specifically categorized under CWE-601 URL Redirection to Untrusted Site. The vulnerability aligns with ATT&CK techniques such as T1566 Phishing and T1071.004 Application Layer Protocol HTTP, as it enables attackers to manipulate user sessions through malicious web interactions. Organizations should implement immediate mitigations including input validation controls, URL sanitization, and network-level restrictions to prevent external domain redirection.
Recommended mitigation strategies include applying the latest SAP security patches and updates, implementing strict URL validation controls within the application, and deploying network-level firewalls to restrict external communication. Organizations should also consider implementing web application firewalls to monitor and block suspicious redirection attempts. Regular security assessments and user awareness training are essential to prevent successful exploitation of this vulnerability. The vulnerability demonstrates the importance of proper input validation and output encoding in preventing server-side request forgery attacks, particularly in enterprise applications where user trust is paramount for system security.