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Software & Hardware Mix: => Linux / Unix / Android => Topic started by: Samker on 17. May 2014., 11:06:16

Title: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: Samker on 17. May 2014., 11:06:16
(http://2.bp.blogspot.com/-EllreivJ0xQ/T6_pVY53oQI/AAAAAAAAgSg/zRDS8KHAeoQ/s1600/linux.jpg)

Linux admins need to get busy patching, as a newly discovered bug has emerged in the kernel's tty handling – and it lets logged-in users crash the system, gain root privileges, or otherwise modify and access data they shouldn't.

This memory corruption flaw is certainly nothing like OpenSSL's remotely exploitable Heartbleed – CVE-2014-0196: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-0196
But this local root hole is problematic where users are sharing the same Linux host in the cloud.

Here's how US-CERT described the issue: https://www.us-cert.gov/ncas/bulletins/SB14-132

“The n_tty_write function in drivers/tty/n_tty.c in the Linux kernel through 3.14.3 does not properly manage tty driver access in the 'LECHO & !OPOST' case, which allows local users to cause a denial of service (memory corruption and system crash) or gain privileges by triggering a race condition involving read and write operations with long strings.”

A user only needs shell access to be in a position to exploit the programming blunder.

The bug was introduced in 2009 with version v2.6.31-rc3 of the kernel. Before that, as noted at this Novell SUSE security discussion, “pty [the pseudo-terminal – El Reg] was writing directly to a line discipline without using buffers”: https://bugzilla.novell.com/show_bug.cgi?id=875690

Ubuntu has been patched: http://www.ubuntu.com/usn/usn-2204-1/ , Red Hat is working on a fix for its Enterprise Linux 6 and Enterprise MRG 2 distos (RH Enterprise Linux 5 isn't affected): https://bugzilla.redhat.com/show_bug.cgi?id=1094232
OpenWall has also patched: http://www.openwall.com/lists/oss-security/2014/05/05/6 Debian's patches will arrive here: https://security-tracker.debian.org/tracker/CVE-2014-0196

There's an unreliable proof-of-concept here: http://bugfuzz.com/stuff/cve-2014-0196-md.c

(ElReg)
Title: Re: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: devnullius on 17. May 2014., 13:08:39
Most misleading picture EVER  :down:

Giving a nitwit Linux... It will cause problems and many many many "how do I..."-phone calls :(

Just saying ;p
Title: Re: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: jheysen on 17. May 2014., 14:43:50
I didn't want to update the servers so soon :/
Title: Re: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: devnullius on 17. May 2014., 15:45:47
I didn't want to update the servers so soon :/

Yeah... Kernel 0.1a works like a charm ;p

:>
Title: Re: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: Samker on 17. May 2014., 18:09:04
Most misleading picture EVER  :down:

...

 :up:

...picture for cogitation...
Title: Re: Linux administrators need to Patch a newly discovered bug in the kernel...
Post by: Melisa on 17. January 2018., 09:39:33
Thanks admin, much appreciated.