Feeds

FreeBSD bug grants local root access

Trivial exploitation

Beginner's guide to SSL certificates

A security researcher has uncovered a security bug in the FreeBSD operating system that allows users with limited privileges to take full control of underlying systems.

The bug in FreeBSD's kqueue notification interface makes it trivial for those with local access to a vulnerable system to gain full root privileges, Przemyslaw Frasunek, an independent security consultant in Poland, told The Register. It affects versions 6.0 through 6.4 of the operating system, the last two versions of which enjoy wide use and continue to be supported by the FreeBSD Foundation.

Versions 7.1 and and beyond are not vulnerable.

Those exploiting the bug must first have local access to a vulnerable system, either as a legitimate user or by exploiting some other flaw (say, a vulnerable PHP script) that gives an attacker a toe-hold in to the targeted system. Frasunek said the vulnerability is trivial to exploit, as a video he posted here suggests.

The bug is the result of a race condition in the FreeBSD kqueue that leads to a NULL pointer dereference in kernel mode. Attackers can cause vulnerable systems to run malware by putting the code in a memory page mapped to address 0x0.

Frasunek said he notified FreeBSD officials on August 29 and has yet to get a response. Robert Watson, a FreeBSD Core Team member, told El Reg that it appeared the email had gotten "lost in the slew" and he expected an advisory to be issued soon. ®

Updated to clarify on versions 6.3 and 6.4 continue to be supported and to add comment from a FreeBSD official.

Remote control for virtualized desktops

More from The Register

next story
Regin: The super-spyware the security industry has been silent about
NSA fingered as likely source of complex malware family
Why did it take antivirus giants YEARS to drill into super-scary Regin? Symantec responds...
FYI this isn't just going to target Windows, Linux and OS X fans
Privacy bods offer GOV SPY VICTIMS a FREE SPYWARE SNIFFER
Looks for gov malware that evades most antivirus
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
HACKERS can DELETE SURVEILLANCE DVRS remotely – report
Hikvision devices wide open to hacking, claim securobods
'Regin': The 'New Stuxnet' spook-grade SOFTWARE WEAPON described
'A degree of technical competence rarely seen'
Home Office: Fancy flogging us some SECRET SPY GEAR?
If you do, tell NOBODY what it's for or how it works
Syrian Electronic Army in news site 'hack' POP-UP MAYHEM
Gigya redirect exploit blamed for pop-rageous ploy
prev story

Whitepapers

Seattle children’s accelerates Citrix login times by 500% with cross-tier insight
Seattle Children’s is a leading research hospital with a large and growing Citrix XenDesktop deployment. See how they used ExtraHop to accelerate launch times.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Business security measures using SSL
Examines the major types of threats to information security that businesses face today and the techniques for mitigating those threats.