Shellshock Attack experiment

Shellshock Attack Experiment First, the experimental description

September 24, 2014, Bash found a serious vulnerability shellshock, which can be used on many systems and can be triggered either remotely or locally. In this experiment, students need to reproduce the attack to understand the vulnerability and answer some questions.

Second, the preparation of knowledge 1. What is Shellshock?

Shellshock, also known as Bashdoor, is a security vulnerability in the widely used bash shell in Unix, which was first disclosed on September 24, 2014. Many Internet daemons, such as Web servers, use Bash to handle certain commands, allowing an attacker to execute arbitrary code on a vulnerable bash version. This could allow an attacker to access the computer system without authorization. --Excerpt from Wikipedia

2. Preparation required for the experiment 1. Environment construction

Download# wget http://labfile.oss.aliyuncs.com/bash-4.1.tar.gz

Complete

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Installation

Link

The installation is done here, and the next step is to detect the presence of a shellshock vulnerability.

$ env x=‘() { :;}; echo vulnerable‘ bash -c "echo this is a test "

If the output is vulnerable, bash is vulnerable.

1. Attack Set-uid Program

The Setuid (Geteuid ()) statement was removed.

The result is that no permissions are obtained

Shellshock Attack experiment