NetBSD ptrace() and if_clone_list() Bugs Disclose Kernel Memory to Local Users
SecurityTracker Alert ID: 1017292|
SecurityTracker URL: http://securitytracker.com/id/1017292
(Links to External Site)
Updated: May 27 2008|
Original Entry Date: Nov 28 2006
Disclosure of authentication information, Disclosure of system information, Disclosure of user information|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): 2.0 - 3.1|
A vulnerability was reported in NetBSD. A local user can read portions of kernel memory.|
A local user can supply a specially crafted PT_LWPINFO request to the ptrace(2) function call to cause kernel memory to be leaked.
A local user can exploit the if_clone_list() function to cause the kernel to disclose up to IFNAMSIZ bytes of uninitialized stack memory.
Ben Hawkes of Suresec Pty. Ltd. reported this ptrace vulnerability. Christer Oberg of BitSec reported the if_clone_list() vulnerability.
A local user can read portions of kernel memory.|
The vendor has issued a fixed kernel.|
The NetBSD advisory is available at:
Vendor URL: www.netbsd.org/ (Links to External Site)
Access control error|
Source Message Contents
Subject: NetBSD Security Advisory 2006-025: Multiple information/memory leakage|
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NetBSD Security Advisory 2006-025
Topic: Multiple information/memory leakage issues
Version: NetBSD-current: source prior to October 27, 2006
NetBSD 3.1: not affected
NetBSD 3.0.2: not affected
NetBSD 3.0.1: affected
NetBSD 3.0: affected
NetBSD 2.1: affected
NetBSD 2.0.*: affected
NetBSD 2.0: affected
Severity: Information/memory leakage.
Fixed: NetBSD-current: October 27, 2006
NetBSD-3-0 branch: October 27, 2006
NetBSD-3 branch: October 27, 2006
NetBSD-2-1 branch: November 19, 2006
NetBSD-2-0 branch: November 19, 2006
NetBSD-2 branch: November 19, 2006
There are multiple information/memory leakage issues present in the
* ptrace memory/information leak
A userspace parameter passed to the ptrace(2) call involving a PT_LWPINFO
request can result in a memory/information leak.
* if_clone_list() information leak
There is a minor kernel memory disclose in if_clone_list() where up to
IFNAMSIZ bytes of uninitialized stack memory are copied out to userland.
Solutions and Workarounds
For all NetBSD versions, you need to obtain fixed kernel sources,
rebuild and install the new kernel, and reboot the system.
The fixed source may be obtained from the NetBSD CVS repository.
The following instructions briefly summarise how to upgrade your
kernel. In these instructions, replace:
ARCH with your architecture (from uname -m), and
KERNCONF with the name of your kernel configuration file.
To update from CVS, re-build, and re-install the kernel:
# cd src
# cvs update sys/kern/sys_process.c \
# ./build.sh kernel=KERNCONF
# mv /netbsd /netbsd.old
# cp sys/arch/ARCH/compile/obj/KERNCONF/netbsd /netbsd
# shutdown -r now
For more information on how to do this, see:
The ptrace memory/information leak was discovered and reported by
Ben Hawkes of Suresec Pty. Ltd.
The if_clone_list() information leak was discovered and reported by
Christer Oberg of BitSec.
2006-11-27 Initial release
Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at
Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.org/ and http://www.NetBSD.org/Security/.
Copyright 2006, The NetBSD Foundation, Inc. All Rights Reserved.
Redistribution permitted only in full, unmodified form.
$NetBSD: NetBSD-SA2006-025.txt,v 1.3 2006/11/27 20:14:45 adrianp Exp $
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