Kernel Bug Lay Undiscovered for Eight Years

Aug 14, 2009

A Linux kernel bug in network socket initialization could allow an attacker to acquire root privileges to inflict damages. The security hole applies to all kernels of the 2.4 and 2.6 series and has been around possibly since 2001.

Source of the bug is a NULL pointer dereference caused by an incorrectly implemented function during socket initialization. Pointers should have redirected the function to a predefined stub routine, but some protocols leave these pointers uninitialized. The list of affected protocols is pretty long: Appletalk, IPX, X.25, IRDA, Bluetooth, ISDN, AX25, SCTP via IPv6 and IUCV, although there may be more.

The kernel validates the pointers before executing most of the relevant functions. However, it was found that the sock_sendpage() routine bybasses the validation and accepts the NULL pointer. An attacker can thereby inflict some damage with code on the first page executed with root privileges. A precondition, however, is that the attacker already has code modification privileges as user, which precludes any remote attack possibilities.

A few exploits were already prepared for the vulnerability, but a relevant kernel patch now exists in Git. Most distros should implement their own security patches for the affected protocols for their delivered kernel versions.

Related content

  • Kernel Protection

    Security vulnerabilities in the kernel often remain undetected. The kernel hacker initiative, Kernel Self-Protection, promotes safe programming techniques to keep attackers off the network, and, if they do slip through the net, mitigate the consequences.

    more »
  • Local Vulnerabilities in Current Kernels

    Recent kernel versions back to the older kernel 2.6.17 may contain a vulnerability that can be exploited by local attackers.

    more »
  • Update: Security Hole in Kernel Allows Privilege Extensions

    A null-pointer dereference in the Linux kernel allows local users to assume root privileges. Brad Spengler, who claims first discovery, announced that he will present a corresponding exploit during the course of the day.

    more »
  • Kernel News

    This month Zack discusses adapting to COVID-19, and l33t security. 

    more »
  • Kernel News

    Chronicler Zack Brown reports on the latest news, views, dilemmas, and developments within the Linux kernel community.

    more »

Comments

  • great post

    Thanks a lot for sharing the article on cash. That's a awesome article. I enjoyed the article a lot while reading. Thanks for sharing such a wonderful article.I want to say very thank you for this great informations. now i understand about it. Thank you !
    http://www.cocoschanel.com
    http://www.gucciguccis.com
    http://www.urboots.com
    http://www.handbags2012.com
    http://www.louisvuittonslv.com
    http://www.uggmalls.com

  • Naivete

    "t's been found, and it's been fixed. In addition it was never exploited, as it was never found until recently, had it been found earlier it would have been fixed earlier.

    If on the other hand it had been known about and exploits available, and it had never been fixed,then there would be something to get upset about."

    The comment above may be a bit naive? Just because it was not found by kernel developers until recently does not mean that the bug may not have been exploited.

  • Why

    It's been found, and it's been fixed. In addition it was never exploited, as it was never found until recently, had it been found earlier it would have been fixed earlier.

    If on the other hand it had been known about and exploits available, and it had never been fixed,then there would be something to get upset about.

  • kernel typo - (I hope)


    Uh, that applies to all kernels of the 2.4 - 2.6 series...

    quote: "2.6, from 2.6.0 up to and including 2.6.30.4"

    I hope this was just a typo, because leaving out that it affects the 2.6 series would be a large blunder.

comments powered by Disqus

Issue 269/2023

Buy this issue as a PDF

Digital Issue: Price $12.99
(incl. VAT)

Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Find SysAdmin Jobs

News

Tag Cloud

Administration Community Desktop Events Hardware Linux Linux Pro Magazine Mobile Programming Software Ubuntu Web Development Windows free software open source