Templates and Alerts

Buffer Overflow Template

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

Table A-2

Template Properties

 

 

 

 

 

 

 

 

 

Name

 

Type

Default Value

 

 

 

 

 

 

priv_uid_list

III

 

0 1 2 3 4 5 9 11

 

 

 

 

 

 

unusual_arg_len

VIII

 

500

 

 

 

 

 

 

pathnames_to_not_watch

I

 

<empty>

 

 

 

 

 

Property: priv_uid_list

A list of system-level user IDs.

This list should contain those users that are considered to have elevated access to the system. Only programs that run with an effective user ID equal to one of the listed integers will be monitored for the use of unusually long arguments or arguments with non-printable characters. In general, the user IDs of other privileged accounts (e.g., Webmaster, News Administrator, etc.) should be added and none of the dfeault UIDs should be removed.

Property: unusual_arg_len

An integer value set to what is considered an unusually long argument length.

This property value can be configured to what is considered an unusually long argument length for privileged setuid executables run on the system, which might indicate a buffer overflow attack.

Property: pathnames_to_not_watch

Pathnames of programs that can be safely ignored.

Any buffer overflow alert for a program whose pathname is matched by a regular expression in this property will be filtered out and not reported.

Alerts generated by this template

“Execute on Stack” on page 135

“Unusual Argument Length” on page 137

“Argument with Non-printable Character” on page 138

Execute on Stack

This template generates and forwards the following alert to a response program when an execute-on-stack condition is detected by the HP-UX 11i kernel:

Table A-3

Execute on Stack Alert Properties

 

 

 

 

 

 

 

 

Response

Alert

Alert

 

 

 

Program

Field

Alert Value/Format

Description

 

Field

 

Argument

Type

 

 

 

 

 

 

 

 

 

 

 

 

 

argv[1]

Template

Integer

0

Unique code assigned to

 

 

code

 

 

the template

 

 

 

 

 

 

 

argv[2]

Version

Integer

2

Version of the template

 

 

 

 

 

 

Appendix A

135

Page 147
Image 147
HP Host Intrusion Detection System (HIDS) manual Execute on Stack, Table A-2 Template Properties, Name Type Default Value