Real Wireless Vulnerability

At ShmooCon one talk discussed a somewhat obvious and not that exciting (to me) feature of Windows wireless networking. I don't consider automatic network connectivity to be a vulnerability, only a bad design choice. However, this morning I read this advisory on a real wireless vulnerability in FreeBSD's (and possible other BSD's) wireless code. From the advisory:

II.  Problem Description

An integer overflow in the handling of corrupt IEEE 802.11 beacon or
probe response frames when scanning for existing wireless networks can
result in the frame overflowing a buffer.

III. Impact

An attacker able broadcast a carefully crafted beacon or probe response
frame may be able to execute arbitrary code within the context of the
FreeBSD kernel on any system scanning for wireless networks.

That's cool. Insert wireless NIC, be 0wn3d. I'm glad I heard about this prior to Black Hat Federal next week.

Comments

Anonymous said…
Patched a few hours ago...

ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-06:05.80211.asc

http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/net80211/ieee80211_ioctl.c
8:54 AM
Anonymous said…
Note that exploiting this issue does not require that a system be connected to a wireless network -- rather, it simply requires that the system scan to determine which networks are available.
9:06 AM
Anonymous said…
Is this the same vul. for which OpenBSD decided that a fix will not be issued?
7:47 AM
Richard Bejtlich said…
I thought that was an issue involving secure levels?
8:40 AM
Anonymous said…
Is this the same vul. for which OpenBSD decided that a fix will not be issued?

no

I thought that was an issue involving secure levels?

yes
3:18 PM
Anonymous said…
I have been keeping my FreeBSD 6.0 system up-to-date using freebsd-update. Is this patch rolled out through the updates issued with freebsd-update or should I update using another source?

I too will be at Black Hat Federal 2006 next week and would like very much not to be owned when I fire up my laptop (although I don't start any of my interfaces at boot, I will probably be looking for some wi-fi at some point).

Jeff
6:46 PM
Richard Bejtlich said…
Jeff - yes. wlan.ko is updated below.

soekris:/root# uname -a
FreeBSD soekris.taosecurity.com 6.0-RELEASE FreeBSD 6.0-RELEASE #0: Thu Nov 3 09:36:13 UTC 2005 root@x64.samsco.home:/usr/obj/usr/src/sys/GENERIC i386

soekris:/root# freebsd-update fetch
Fetching public key...
Fetching updates signature...
Fetching updates...
Fetching hash list signature...
Fetching hash list...
Examining local system...
Fetching updates...
/boot/kernel/ipfw.ko...
/boot/kernel/kernel...
/boot/kernel/linker.hints...
/boot/kernel/nfsclient.ko...
/boot/kernel/wlan.ko...
/usr/bin/cpio...
/usr/bin/edit...
/usr/bin/ee...
/usr/bin/ree...
/usr/bin/texindex...
/usr/share/man/man1/cpio.1.gz...
Updates fetched


To install these updates, run: '/usr/local/sbin/freebsd-update install'
soekris:/root# freebsd-update install
Backing up /boot/kernel/ipfw.ko...
Installing new /boot/kernel/ipfw.ko...
Backing up /boot/kernel/kernel...
Installing new /boot/kernel/kernel...
Backing up /boot/kernel/linker.hints...
Installing new /boot/kernel/linker.hints...
Backing up /boot/kernel/nfsclient.ko...
Installing new /boot/kernel/nfsclient.ko...
Backing up /boot/kernel/wlan.ko...
Installing new /boot/kernel/wlan.ko...
Backing up /usr/bin/cpio...
Installing new /usr/bin/cpio...
Backing up /usr/bin/edit...
Installing new /usr/bin/edit...
Backing up /usr/bin/ee...
Recreating hard link from /usr/bin/edit to /usr/bin/ee...
Backing up /usr/bin/ree...
Recreating hard link from /usr/bin/edit to /usr/bin/ree...
Backing up /usr/bin/texindex...
Installing new /usr/bin/texindex...
Backing up /usr/share/man/man1/cpio.1.gz...
Installing new /usr/share/man/man1/cpio.1.gz...
soekris:/root# shutdown -r now

soekris:/root# uname -a
FreeBSD soekris.taosecurity.com 6.0-SECURITY FreeBSD 6.0-SECURITY #0: Wed Jan 18 05:55:04 UTC 2006 root@builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
7:32 PM
Post a Comment

Popular posts from this blog

Zeek in Action Videos

Image
This is a quick note to point blog readers to my Zeek in Action YouTube video series for the Zeek network security monitoring project .  Each video addresses a topic that I think might be of interest to people trying to understand their network using Zeek and adjacent tools and approaches, like Suricata, Wireshark, and so on.  I am especially pleased with Video 6 on monitoring wireless networks . It took me several weeks to research material for this video. I had to buy new hardware and experiment with a Linux distro that I had not used before -- Parrot .  Please like and subscribe, and let me know if there is a topic you think might make a good video.
Read more

MITRE ATT&CK Tactics Are Not Tactics

Image
Just what are "tactics"? Introduction MITRE ATT&CK  is a great resource, but something about it has bothered me since I first heard about it several years ago. It's a minor point, but I wanted to document it in case it confuses anyone else. The MITRE ATT&CK Design and Philosophy document from March 2020 says the following: At a high-level, ATT&CK is a behavioral model that consists of the following core components: • Tactics, denoting short-term, tactical adversary goals during an attack; • Techniques, describing the means by which adversaries achieve tactical goals; • Sub-techniques, describing more specific means by which adversaries achieve tactical goals at a lower level than techniques; and • Documented adversary usage of techniques, their procedures, and other metadata. My concern is with MITRE's definition of "tactics" as "short-term, tactical adversary goals during an attack," which is oddly recursive. The key word in the tacti...
Read more

New Book! The Best of TaoSecurity Blog, Volume 4

Image
  I've completed the TaoSecurity Blog book series . The new book is  The Best of TaoSecurity Blog, Volume 4: Beyond the Blog with Articles, Testimony, and Scholarship .  It's available now for Kindle , and I'm working on the print edition.  I'm running a 50% off promo on Volumes 1-3 on Kindle through midnight 20 April. Take advantage before the prices go back up. I described the new title thus: Go beyond TaoSecurity Blog with this new volume from author Richard Bejtlich. In the first three volumes of the series, Mr. Bejtlich selected and republished the very best entries from 18 years of writing and over 18 million blog views, along with commentaries and additional material.  In this title, Mr. Bejtlich collects material that has not been published elsewhere, including articles that are no longer available or are stored in assorted digital or physical archives. Volume 4 offers early white papers that Mr. Bejtlich wrote as a network defender, either for technica...
Read more