Full Disclosure mailing list archives
Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory
From: Wojciech Purczynski <cliph () isec pl>
Date: Tue, 2 Dec 2003 12:10:33 +0100 (CET)
Recently multiple servers of the Debian project were compromised using a Debian developers account and an unknown root exploit. Forensics revealed a burneye encrypted exploit. Robert van der Meulen managed to decrypt the binary which revealed a kernel exploit. Study of the exploit by the RedHat and SuSE kernel and security teams quickly revealed that the exploit used an integer overflow in the brk system call. Using this bug it is possible for a userland program to trick the kernel into giving access to the full kernel address space. This problem was found in September by Andrew Morton, but unfortunately that was too late for the 2.4.22 kernel release.
This is not an integer overflow bug. do_brk() doesn't verify its arguments at all, allowing to create arbitrarily large virtual memory mapping (vma) consuming kernel memory. Regards, wp -- Wojciech Purczynski iSEC Security Research http://isec.pl/ _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
Current thread:
- [SECURITY] [DSA-403-1] userland can access Linux kernel memory debian-security-announce (Dec 01)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Florian Weimer (Dec 01)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Roman Drahtmueller (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Florian Weimer (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Paul Starzetz (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Roman Drahtmueller (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Cedric Blancher (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Wojciech Purczynski (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Florian Weimer (Dec 02)
- Re: [SECURITY] [DSA-403-1] userland can access Linux kernel memory Florian Weimer (Dec 01)