CVE-2018-20735 - Improper Authentication

Severity

72%

Complexity

39%

Confidentiality

165%

** DISPUTED ** An issue was discovered in BMC PATROL Agent through 11.3.01. It was found that the PatrolCli application can allow for lateral movement and escalation of privilege inside a Windows Active Directory environment. It was found that by default the PatrolCli / PATROL Agent application only verifies if the password provided for the given username is correct; it does not verify the permissions of the user on the network. This means if you have PATROL Agent installed on a high value target (domain controller), you can use a low privileged domain user to authenticate with PatrolCli and then connect to the domain controller and run commands as SYSTEM. This means any user on a domain can escalate to domain admin through PATROL Agent. NOTE: the vendor disputes this because they believe it is adequate to prevent this escalation by means of a custom, non-default configuration.

** DISPUTED ** An issue was discovered in BMC PATROL Agent through 11.3.01. It was found that the PatrolCli application can allow for lateral movement and escalation of privilege inside a Windows Active Directory environment. It was found that by default the PatrolCli / PATROL Agent application only verifies if the password provided for the given username is correct; it does not verify the permissions of the user on the network. This means if you have PATROL Agent installed on a high value target (domain controller), you can use a low privileged domain user to authenticate with PatrolCli and then connect to the domain controller and run commands as SYSTEM. This means any user on a domain can escalate to domain admin through PATROL Agent. NOTE: the vendor disputes this because they believe it is adequate to prevent this escalation by means of a custom, non-default configuration.

CVSS 3.0 Base Score 7.8. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 7.2. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:C/I:C/A:C).

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

First reported 6 years ago

2019-01-17 20:29:00

Last updated 5 years ago

2019-10-03 00:03:00

Affected Software

BMC Software PATROL Agent

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