
University of Cambridge researcher
Robert Watson has published a paper at the First USENIX Workshop On Offensive Technology in which he describes serious
vulnerabilities in OpenBSD's Systrace, Sudo, Sysjail, the TIS GSWTK framework, and CerbNG. The technique is also effective against many commercially available anti-virus systems. His slides include sample exploit code that bypasses access control, virtualization, and intrusion detection in under 20 lines of C code consisting solely of memcpy() and fork().
Sysjail has now withdrawn their software, recommending against any use, and NetBSD has disabled
Systrace by default in their upcoming release.
Member since:
2006-04-25
.. that this is only exploitable on multiprocessor systems.
Also, it seems that there is a solution available:
There is a straight forward solution for this problem. The initial
prototype of Systrace had a look-aside buffer in the kernel for
copyin. I told Robert about this, not sure if he mentioned that in
his paper or not. There obviously would be some associated
performance impacts. (Niels Provos, on the OpenBSD mailing list)
Still pretty serious though.