Vulnerabilities > CVE-2021-21480 - Code Injection vulnerability in SAP Manufacturing Integration and Intelligence

047910
CVSS 9.0 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
low complexity
sap
CWE-94
critical

Summary

SAP MII allows users to create dashboards and save them as JSP through the SSCE (Self Service Composition Environment). An attacker can intercept a request to the server, inject malicious JSP code in the request and forward to server. When this dashboard is opened by users having at least SAP_XMII Developer role, malicious content in the dashboard gets executed, leading to remote code execution in the server, which allows privilege escalation. The malicious JSP code can contain certain OS commands, through which an attacker can read sensitive files in the server, modify files or even delete contents in the server thus compromising the confidentiality, integrity and availability of the server hosting the SAP MII application. Also, an attacker authenticated as a developer can use the application to upload and execute a file which will permit them to execute operating systems commands completely compromising the server hosting the application.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Manipulating User-Controlled Variables
    This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An attacker can override environment variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the attacker can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.