** Description changed: ssh is now handling by upstart native jobs(with /etc/init/ssh.conf configs), and "respawn" stanza. This is great works. But this behavior is not familiar for security paranoid. Scenario: - - sshd is enougth to berief, but this is not perfect. In future, if we have got vuln for exploiting sshd, that can "randomly" type atacks (e.g.: buffer overflow, it is exploitable with probabilistic atacks, like brute force.). - - endless respawning is weaken for these "memory address brute force" atacks. + - sshd is enougth to berief, but this is not perfect. In future, if we have got vuln for exploiting sshd, that can "randomly" type atacks (e.g.: buffer overflow, it is exploitable with probabilistic atacks, like brute force.). + - endless respawning is weaken for these "memory address brute force" atacks. - IMHO, when using "respawn" stanza, it needs something "limit" stanza (e.g.: respawn limit 60 30) or any other way ( e.g.: MAC by AppArmor). limitation by "limit" can mitigates(atack speed limitation) probabilistic atacks. This limitation provides potential over-limit DoS, but unlimited respawning is dangerous. - # May be, we have to improvement upstart respawn stanza, like "respawn delay" feature... + IMHO, when using "respawn" stanza, it needs something "limit" stanza (e.g.: respawn limit 60 30) + or any other way ( e.g.: MAC by AppArmor). - ....Yes, this wish is not only ssh services. But ssh is most popular + - internet accessible services. + limitation by "limit" can mitigates(atack speed limitation) probabilistic atacks. + This limitation provides potential over-limit DoS, but unlimited respawning is dangerous. + + # May be, we have to improvement upstart respawn stanza, like "respawn delay" + # feature...(see https://bugs.launchpad.net/upstart/+bug/252997) + + ....Yes, this wish is not only ssh services. But ssh is most popular + internet accessible services. + In general cases, administrator use "ufw limit ssh" settings. Its not hazardous.
-- [LUCID] We need "limit" Upstart-ed ssh respawning https://bugs.launchpad.net/bugs/533352 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
