CAPEC 9

Summary

Attack Execution Flow

1. Attacker identifies command utilities exposed by the target host.

2. On the probing stage, the attacker interacts with the command utility and observes the results of its input. The attacker's goal is to uncover a buffer oveflow in the command utility. For instance the attacker may find that input data are not properly validated.

3. The attacker finds a buffer overflow vulnerability in the command utility and tries to exploit it. He crafts malicious code and injects it using the command utility. The attacker can at worst execute remote code on the target host.

Likelihood: High

Description

Skill or Knowledge Level: Low

An attacker can simply overflow a buffer by inserting a long string into an attacker-modifiable injection vector. The result can be a DoS.

High : Exploiting a buffer overflow to inject malicious code into the stack of a software system or even the heap can require a higher skill level.

The attacker can probe for services available on the target host. Many services may expose a command utility. For instance Telnet is a service which can be invoked through a command shell.

Carefully review the service's implementation before making it available to user. For instance you can use manual or automated code review to uncover vulnerabilities such as buffer overflow.

Use a language or compiler that performs automatic bounds checking.

Use an abstraction library to abstract away risky APIs. Not a complete solution.

Compiler-based canary mechanisms such as StackGuard, ProPolice and the Microsoft Visual Studio /GS flag. Unless this provides automatic bounds checking, it is not a complete solution.

Operational: Use OS-level preventative functionality. Not a complete solution.

Apply the latest patches to your user exposed services. This may not be a complete solution, specially against zero day attack.

Do not unnecessarily expose services.

CWE - Buffer Errors