CVE-2020-5194 - Incorrect Authorization

Severity

54%

Complexity

27%

Confidentiality

41%

The zip API endpoint in Cerberus FTP Server 8 allows an authenticated attacker without zip permission to use the zip functionality via an unrestricted API endpoint. Improper permission verification occurs when calling the file/ajax_download_zip/zip_name endpoint. The result is that a user without permissions can zip and download files even if they do not have permission to view whether the file exists.

The zip API endpoint in Cerberus FTP Server 8 allows an authenticated attacker without zip permission to use the zip functionality via an unrestricted API endpoint. Improper permission verification occurs when calling the file/ajax_download_zip/zip_name endpoint. The result is that a user without permissions can zip and download files even if they do not have permission to view whether the file exists.

CVSS 3.1 Base Score 5.4. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N).

CVSS 2.0 Base Score 5.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:S/C:P/I:P/A:N).

Demo Examples

Incorrect Authorization

CWE-863

The following code could be for a medical records application. It displays a record to already authenticated users, confirming the user's authorization using a value stored in a cookie.


               
}
}
setcookie("role", $role, time()+60*60*2);
die("\n");
DisplayMedicalHistory($_POST['patient_ID']);
die("You are not Authorized to view this record\n");

The programmer expects that the cookie will only be set when getRole() succeeds. The programmer even diligently specifies a 2-hour expiration for the cookie. However, the attacker can easily set the "role" cookie to the value "Reader". As a result, the $role variable is "Reader", and getRole() is never invoked. The attacker has bypassed the authorization system.

Overview

First reported 5 years ago

2020-01-14 14:15:00

Last updated 5 years ago

2020-01-24 14:16:00

Affected Software

Cerberus FTP Server 8.0

8.0

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