Breaking

Revisiting an Old Friend: Shell Globbing

One interesting observation we make when testing complex environments is that at the bottom of huge technology stacks, there is usually a handful of shell scripts doing interesting stuff. More often than not these helper scripts are started as part of cron jobs running as root and perform basic administrative tasks like compressing and copying log files or deleting leftover files in temporary directories. Of course, these high privileges make them an interesting target for privilege escalation attacks and one class of vulnerability we reliably encounter in shell scripts is unsafe handling of globbing or filename expansions. Continue reading “Revisiting an Old Friend: Shell Globbing”

Continue reading
Building

IPv6 Hardening Guide for Linux Servers

We were recently approached by a customer asking us for support along the lines of “do you have any recommendations as for strict hardening of IPv6 parameters on Linux systems?”. It turned out that the systems in question process quite sensitive data and are located in certain, not too big network segments with very high security requirements.

Continue reading “IPv6 Hardening Guide for Linux Servers”

Continue reading
Building

Security Implications of Using IPv6 GUAs Only

When planning for IPv6 addressing, many organizations – rightfully & wisely – decide to go with global unicast addresses (GUAs) only (hence not to use unique local addresses/ULAs as of RFC 4193 at all), in order to avoid address selection hell or just for simplicity & consistency reasons. This post discusses security implications and complementary security controls of such an approach.

Continue reading “Security Implications of Using IPv6 GUAs Only”

Continue reading