Templates and Alerts

Repeated Failed su Commands Template

 

Repeated Failed su Commands Template

The vulnerability

The system su(1) command allows one user to assume the identity of another user by

addressed by this

entering that user’s password. An attacker can attempt to gain root privileges by

template

running the su command and guessing the root password.

How this template

The template monitors for repeated failed attempts to change user IDs. The template

addresses the

generates an alert when a given number of failed change user id attempts occurs for a

vulnerability

specified target user.

How this template This template supports the following properties: is configured

Table A-24

Template Properties

 

 

 

 

 

 

 

Name

Type

Default Value

 

 

 

 

 

max_failed_su

VIII

2

 

 

 

 

 

fail_interval

VI

86400

 

 

 

 

Properties

Property: max_failed_su

 

The number of failed su attempts that is exceeded by a user to su to any user.

Property: fail_interval (in seconds)

The time interval over which the failed su attempts must occur to generate an alert.

The default settings will cause an alert to be generated when more than two su failures by a user occur within 24 hours (86400 seconds = 24 hours).

Alerts generated

• “Repeated Failed su Attempts” on page 176

 

by this template

 

 

 

 

 

 

 

Repeated Failed su Attempts

 

 

 

 

This template generates and forwards the following alerts to a response program when

 

 

 

repeated failed su attempts are detected:

 

Table A-25

Repeated Failed Su Attempts Alert Properties

 

 

 

 

 

 

 

 

 

Response

 

Alert

Alert

 

 

 

Program

 

Field

Alert Value/Format

Description

 

 

Field

 

Argument

 

Type

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

argv[1]

 

Template

Integer

9

Unique code assigned to

 

 

 

code

 

 

template

 

 

 

 

 

 

 

 

argv[2]

 

Version

Integer

2

Version of the template

 

 

 

 

 

 

 

 

argv[3]

 

Severity

Integer

2 if one of the targets is user root or

Severity

 

 

 

 

 

ids.

 

 

 

 

 

 

3 otherwise.

 

 

 

 

 

 

 

 

176

Appendix A

Page 188
Image 188
HP Host Intrusion Detection System (HIDS) manual Repeated Failed su Commands Template, Repeated Failed su Attempts, 176