An issue was discovered in the base64d function in the SMTP listener in
Exim before 4.90.1. By sending a handcrafted message, a buffer overflow
may happen. This can be used to execute code remotely.
Exim might be your default mail daemon (MTA) and might be installed due to
package dependencies. Default should have it only listening to localhost,
so this issue would not be exploitable unless the attacker is already on
You can see if you even have a mail daemon running by checking to see if
you have something listening on port 25.