In kernel-programming we should avoid doing call_usermodehelper() which allows to execute a command from kernel-space. And sometimes we even want to call this function within a systemcall.  Normally, we really don't wanna do this. But, desperate times require extraordinary methods.

When I first tried to execute call_usermodehelper() within a systemcall() I got a kernel failure. So I googled and what I found was:

I am currently writing a work about containers and I found this amazing blog which explains containers in 500 lines of code(and about 3000 lines of very well structured text). I can definitely recommend Lizzies-Blog.

Eric Dumazet of Google found a very dangerous remote execution bug in the Linux Kernel. It's located in the recv-syscall with the MSG_PEEK-flag set. Attackers can remotely execute code on the target..

I used a google-dork to find vulnerable software:

MSG_PEEK filetype:c

And found some possible targets:

The latest wikileaks revealings gave also insights about an interesting bug in cisco products.  No I am not talking about the bug in the Cisco Cluster Management Protocol (CMP). I am talking about the open telnet ports.Ten years ago it was already recommended to use ssh instead and there are still so many devices out t

It's 3/14 - Happy PI Day

The Electronic Frontier Foundation released guidelines for protecting your data when you pass the U.S. Border.

During my research about update mechanisms of open-source software I discovered vulnerabilities in OpenElec.

If I enable postscreen on a Debian-Host I'll get this strange message in my mail.log:

Feb 13 08:38:37 tardis postfix/postscreen[17453]: close database /var/lib/postfix/postscreen_cache.db: No such file or directory (possible Berkeley DB bug)

It looks like the postscreen_cache.db-file is located in /var/lib/postfix instead of the postfix-jail /var/spool/postfix/var/lib/postfix. So we can fix it by moving the file into the jail: