CVE-2021-27610 - Improper Authentication

Severity

98%

Complexity

39%

Confidentiality

98%

SAP NetWeaver ABAP Server and ABAP Platform, versions - 700, 701, 702, 731, 740, 750, 751, 752, 753, 754, 755, 804, does not create information about internal and external RFC user in consistent and distinguished format, which could lead to improper authentication and may be exploited by malicious users to obtain illegitimate access to the system.

CVSS 3.1 Base Score 9.8. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 7.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:P/A:P).

Demo Examples

Improper Authentication

CWE-287

The following code intends to ensure that the user is already logged in. If not, the code performs authentication with the user-provided username and password. If successful, it sets the loggedin and user cookies to "remember" that the user has already logged in. Finally, the code performs administrator tasks if the logged-in user has the "Administrator" username, as recorded in the user cookie.


               
}
}
ExitError("Error: you need to log in first");
);
);
DoAdministratorTasks();

Unfortunately, this code can be bypassed. The attacker can set the cookies independently so that the code does not check the username and password. The attacker could do this with an HTTP request containing headers such as:


               
[body of request]

By setting the loggedin cookie to "true", the attacker bypasses the entire authentication check. By using the "Administrator" value in the user cookie, the attacker also gains privileges to administer the software.

Improper Authentication

CWE-287

Overview

Type

SAP NetWeaver AS ABAP

First reported 3 years ago

2021-06-16 15:15:00

Last updated 3 years ago

2021-06-23 18:28:00

Affected Software

SAP NetWeaver AS ABAP 752

752

SAP NetWeaver AS ABAP 753

753

SAP NetWeaver AS ABAP 754

754

SAP NetWeaver AS ABAP 700

700

SAP NetWeaver AS ABAP 731

731

SAP NetWeaver AS ABAP 804

804

SAP NetWeaver AS ABAP 750

750

SAP NetWeaver AS ABAP 740

740

SAP NetWeaver AS ABAP 751

751

SAP NetWeaver AS ABAP 701

701

SAP NetWeaver AS ABAP 702

702

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