CVE-2021-27600 in Manufacturing Execution
Summary
by MITRE • 04/13/2021
SAP Manufacturing Execution (System Rules), versions - 15.1, 15.2, 15.3, 15.4, allows an authorized attacker to embed malicious code into HTTP parameter and send it to the server because SAP Manufacturing Execution (System Rules) tab does not sufficiently encode some parameters, resulting in Stored Cross-Site Scripting (XSS) vulnerability. The malicious code can be used for different purposes. e.g., information can be read, modified, and sent to the attacker. However, availability of the server cannot be impacted.
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Analysis
by VulDB Data Team • 04/17/2021
SAP Manufacturing Execution System Rules component contains a critical stored cross-site scripting vulnerability that affects versions 15.1 through 15.4. This vulnerability stems from insufficient input validation and output encoding within the system rules tab functionality where user-supplied HTTP parameters are not adequately sanitized before being stored and subsequently rendered back to users. The flaw exists in the web application layer where the application fails to properly encode or escape special characters in user-controllable input fields, creating an environment where malicious scripts can be persistently stored and executed within the context of other users' browsers.
The technical implementation of this vulnerability allows an authenticated attacker with appropriate privileges to inject malicious JavaScript code through HTTP parameters that are processed by the system rules tab. When the malicious payload is submitted and stored within the application's database or storage mechanisms, it becomes persistent and executes whenever other users view the affected data or interact with the system rules interface. This stored XSS vulnerability operates at the application level and specifically targets the web user interface components where system rules are configured and displayed. The vulnerability falls under CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding, and aligns with ATT&CK technique T1566.001 for initial access through malicious inputs.
The operational impact of this vulnerability extends beyond simple data theft or modification capabilities. An attacker could potentially extract sensitive session cookies, redirect users to malicious domains, perform actions on behalf of authenticated users, or harvest confidential manufacturing data from the system. The attack vector requires authentication and the attacker must have access to the system rules functionality, but once exploited, the consequences can be severe for operational technology environments. The vulnerability does not affect system availability directly but can compromise the integrity and confidentiality of the manufacturing execution system, potentially leading to production disruptions, data manipulation, or unauthorized access to critical manufacturing processes.
Organizations should implement immediate mitigations including input validation and output encoding controls to sanitize all user-supplied parameters before storage and rendering. The recommended approach involves implementing proper HTML escaping mechanisms, using Content Security Policy headers, and ensuring all user-controllable inputs undergo strict validation. SAP has released patches and updates to address this vulnerability, and organizations should prioritize applying these security fixes to prevent exploitation. Additionally, network segmentation, monitoring for suspicious parameter submissions, and user access controls should be implemented as defensive measures. Regular security assessments and penetration testing of manufacturing execution systems are essential to identify similar vulnerabilities in operational technology environments where the stakes are high for both business continuity and physical process safety. The vulnerability represents a significant risk to industrial control systems and requires immediate attention from security teams responsible for protecting manufacturing infrastructure.