FreeBSD bug gives untrusted root access

'Unbelievably simple' exploit


A security bug in the latest version of FreeBSD can be exploited to grant unprivileged users complete control over the operating system, a German researcher said Monday.

The flaw is present in FreeBSD 8.0 and is known to affect versions 7.1 and 7.2 of the open-source OS, Nikolaos Rangos told The Register. He said it was "unbelievably simple" to exploit. Shortly after he disclosed the flaw on the Full Disclosure mailing list, other researchers said they were able to confirm the bug.

FreeBSD Security Officer Colin Percival said the Full Disclosure post was the first his team had heard of the reported vulnerability. The team is currently investigating.

The bug resides in FreeBSD's run-time link editor. A binary run by an unprivileged user can be executed with administrative privileges in a restricted environment, Rangos said. That allows the user to obtain root access to the system. All that's required to run the exploit code, which Rangos included in his post, is a command shell.

To exploit the bug, hackers would need local access to the vulnerable machine. To use the attack code remotely, it's conceivable it could be used in concert with another vulnerability, such as one residing in a web application running on the box.

Rangos speculated a fix would be coming shortly.

"The bug is in the most recent versions of FreeBSD and normally local root vulnerabilities are quickly patched by the FreeBSD maintainers," he said. ®

Update

FreeBSD's Percival has issued an advisory here. It includes a patch that he says may or may not be final. He writes: "It is even possible (although highly doubtful) that this patch does not fully fix the issue or introduces new issues -- in short, use at your own risk (even more than usual)."

Similar topics


Other stories you might like

  • OpenID-based security features added to GitHub Actions as usage doubles

    Single-use tokens and reusable workflows explained at Universe event

    GitHub Universe GitHub Actions have new security based on OpenID, along with the ability to create reusable workflows, while usage has nearly doubled year on year, according to presentations at the Universe event.

    The Actions service was previewed three years ago at Universe 2018, and made generally available a year later. It was a huge feature, building automation into the GitHub platform for the first time (though rival GitLab already offered DevOps automation).

    It require compute resources, called runners, which can be GitHub-hosted or self-hosted. Actions are commands that execute on runners. Jobs are a sequence of steps that can be Actions or shell commands. Workflows are a set of jobs which can run in parallel or sequentially, with dependencies. For example, that deployment cannot take place unless build and test is successful. Actions make it relatively easy to set up continuous integration or continuous delivery, particularly since they are cloud-hosted and even a free plan offers 2,000 automation minutes per month, and more than that for public repositories.

    Continue reading
  • REvil gang member identified living luxury lifestyle in Russia, says German media

    Die Zeit: He's got a Beemer, a Bitcoin watch and a swimming pool

    German news outlets claim to have identified a member of the infamous REvil ransomware gang – who reportedly lives the life of Riley off his ill-gotten gains.

    The gang member, nicknamed Nikolay K by Die Zeit newspaper and the Bayerische Rundfunk radio station, reportedly owns a €70,000 watch with a Bitcoin address engraved on its face and rents yachts for €1,300 a day whenever he goes on holiday.

    "He seems to prefer T-shirts from Gucci, luxurious BMW sportscars and large sunglasses," reported Die Zeit, which partly identified him through social media videos posted by his wife.

    Continue reading
  • A Windows 11 tsunami? No, more of a ripple as Microsoft's latest OS hits 5% PC market

    Next version of Windows 10 looms around the corner

    Microsoft's Windows 11 OS has notched up a respectable near 5 per cent of PCs surveyed by AdDuplex, as another Dev Channel build was unleashed with new features for the favoured few.

    With less than a month of General Availability under its belt, Windows 11 now accounts for 4.8 per cent of "modern" PCs (Windows Insiders running the OS account for 0.3 per cent) according to the ad platform. The figure is up from the 1.3 per cent in September, which was Insider-only and points to some migration to the production version of the software.

    The figure is both an indicator of Microsoft's cautious approach to releasing its wares and the limited amount of hardware that can actually run the round-cornered OS.

    Continue reading

Biting the hand that feeds IT © 1998–2021