23 decembrie 2015

"Disable yama" in Ubuntu

 cat /proc/sys/kernel/yama/ptrace_scope 

As Linux grows in popularity, it will become a larger target for malware. One particularly troubling weakness of the Linux process interfaces is that a single user is able to examine the memory and running state of any of their processes. For example, if one application (e.g. Pidgin) was compromised, it would be possible for an attacker to attach to other running processes (e.g. Firefox, SSH sessions, GPG agent, etc) to extract additional credentials and continue to expand the scope of their attack without resorting to user-assisted phishing. This is not a theoretical problem. SSH session hijacking and arbitrary code injection attacks already exist and remain possible if ptrace is allowed to operate as before. Since ptrace is not commonly used by non-developers and non-admins, system builders should be allowed the option to disable this debugging system.

ptrace_scope value 0 => disable this security, while value 1 is the default after each booting

 echo 0 > /proc/sys/kernel/yama/ptrace_scope