Description of problem: Vulnerability : userland can access full kernel memory Problem type : local Debian-specific: no CVE Id(s) : CAN-2003-0961 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. http://lists.debian. org/debian-security-announce/debian-security-announce-2003/msg00212. html Version-Release number of selected component (if applicable): kernel-2.4.22-1.2115.nptl How reproducible: Get the exploit or look at debian.org ;-) Actual results: Patched in 2.4.23 for the 2.4 tree. Expected results: Update to 2.4.23 or backport the patch. And don't forget the patches for the older Red Hat versions. Additional info: Someone might slap me if I'm wrong, but I can't find any backport in the actual Fedora Core 1 kernel...
--- linux-2.4.22/mm/mmap.c.orig 2003-12-01 22:45:21.000000000 +0100 +++ linux-2.4.22/mm/mmap.c 2003-12-01 22:47:23.000000000 +0100 @@ -1041,6 +1041,9 @@ if (!len) return addr; + if ((addr + len) > TASK_SIZE || (addr + len) < addr) + return -EINVAL; + /* * mlock MCL_FUTURE? */
not vulnerable - patch exists in linux-2.4.18-smallpatches.patch (2.4.22-1.2115.nptl)