Friday May 31, 2013

CVE-2013-2850: Remote heap buffer overflow in iSCSI target subsystem.

We have just released a rebootless update to deal with a critical security vulnerability:

CVE-2013-2850: Remote heap buffer overflow in iSCSI target subsystem.

If an iSCSI target is configured and listening on the network, a remote
attacker can corrupt heap memory, and gain kernel execution control over
the system and gain kernel code execution.

As this vulnerability is exploitable by remote users, Ksplice is issuing an update for all affected kernels immediately.

This update was embargoed for release until today (May 30th), when the information regarding this vulnerability has been made public. We are pushing updates for Ubuntu Precise, Quantal, and Raring, as well as for Debian Wheezy, Fedora 17 and Fedora 18. This bug was introduced in version 3.1 of the Linux kernel and so does not affect Oracle UEK kernels, or any RedHat 6 derivatives or earlier.

We recommend Oracle Linux Premier Support for receiving rebootless kernel updates via Ksplice.

Wednesday May 15, 2013

Ksplice update for CVE-2013-2094

This is a 0-day local privilege escalation found by Tommi Rantala while fuzzing the kernel using Trinity. The cause of that oops was patched in 3.8.10 in commit 8176cced706b5e5d15887584150764894e94e02f.

'spender' on Reddit has an interesting writeup on the details of this exploit.

We've already shipped this for Fedora 17 and 18 for the 3.8 kernel, and an update for Ubuntu 13.04 will ship as soon as Canonical releases their kernel.

We have a policy of only shipping updates that the vendor has shipped, but in this case we are shipping an update for this CVE for Oracle's UEK2 kernel early. Oracle is in the process of preparing an updated UEK2 kernel with the same fix and will be released through the normal channels.

All customers with Oracle Linux Premier Support should use Ksplice to update their kernel as soon as possible.

[EDITED 2013-05-15]: We have now released an early update for Oracle RHCK 6, RedHat Enterprise Linux 6, Scientific Linux 6 and CentOS 6.

[EDITED 2013-05-15]: We have released an early update for Wheezy. Additionally, Ubuntu Raring, Quantal and Precise have released their kernel, so we have released updates for them.

Wednesday Jun 30, 2010

Let's Play Vulnerability Bingo!

Dear Fellow System Administrators,

I like excitement in my life. I go on roller coasters, I ride my bike without a helmet, I make risky financial decisions. I treat my servers no differently. When my Linux vendor releases security updates, I think: I could apply these patches, but why would I? If I did, I'd have to coordinate with my users to schedule a maintenance window for 2am on a Sunday and babysit those systems while they reboot, which is seriously annoying, hurts our availability, and interrupts my beauty sleep (and trust me, I need my beauty sleep). Plus, where's the fun in having a fully-patched system? Without open vulnerabilities, how else would I have won a ton of money in my office's Vulnerability Bingo games?

vulnerability bingo card

How can I get in on some Vulnerability Bingo action, you ask? Simple: get yourself some bingo cards, be sure not to patch your systems, and place chips on appropriate squares when your machines are compromised. Or, as a fun variant, place chips when your friends' machines get compromised! For the less adventurous, place chips as relevant Common Vulnerabilities and Exposures are announced.

What's really great is the diversity of vulnerabilities. In 2009 alone, Vulnerability Bingo featured:

physically proximate denial of service attacks (CVE-2009-1046).

local denial of service attacks (CVE-2009-0322, CVE-2009-0031, CVE-2009-0269, CVE-2009-1242, CVE-2009-2406, CVE-2009-2407, CVE-2009-2287, CVE-2009-2692, CVE-2009-2909, CVE-2009-2908, CVE-2009-3290, CVE-2009-3547, CVE-2009-3621, CVE-2009-3620) coming in at least 5 great flavors: faults, memory corruption, system crashes, hangs, and the kernel OOPS!

And the perennial favorite, remote denial of service attacks (CVE-2009-1439, CVE-2009-1633, CVE-2009-3613, CVE-2009-2903) including but not limited to system crashes, IOMMU space exhaustion, and memory consumption!

How about leaking potentially sensitive information from kernel memory (CVE-2009-0676, CVE-2009-3002, CVE-2009-3612, CVE-2009-3228) and remote access to potentially sensitive information from kernel memory (CVE-2009-1265)?

Perhaps I can interest you in some privilege escalation (CVE-2009-2406, CVE-2009-2407, CVE-2009-2692, CVE-2009-3547, CVE-2009-3620), or my personal favorites, arbitrary code execution (CVE-2009-2908) and unknown impact (CVE-2009-0065, CVE-2009-1633, CVE-2009-3638).

Sometimes you get a triple threat like CVE-2009-1895, which "makes it easier for local users to leverage the details of memory usage to (1) conduct NULL pointer dereference attacks, (2) bypass the mmap_min_addr protection mechanism, or (3) defeat address space layout randomization (ASLR)". Three great tastes that taste great together -- and a great multi-play Bingo opportunity!

Linux vendors release kernel security updates almost every month (take Red Hat for example), so generate some cards and get in on the action before you miss the next round of exciting CVEs!

Happy Hacking,

Ben Bitdiddle
System Administrator
HackMe Inc.



Tired of rebooting to update systems? So are we -- which is why we invented Ksplice, technology that lets you update the Linux kernel without rebooting. It's currently available as part of Oracle Linux Premier Support, Fedora, and Ubuntu desktop. This blog is our place to ramble about technical topics that we (and hopefully you) think are interesting.


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