Sudo Flaw Lets Linux Users Run Commands As Root Even When They're Restricted

exadra37

Paulo Renato

Posted on October 15, 2019

Sudo Flaw Lets Linux Users Run Commands As Root Even When They're Restricted

In this article we can read how Joe Vennix of Apple Information Security uncovered a security flaw on the sudo command, that allows a malicious user or application to run any command as the root user on a Linux system.

TLDR

The security policy vulnerability

The vulnerability in question is a sudo security policy bypass issue that could allow a malicious user or a program to execute arbitrary commands as root on a targeted Linux system even when the "sudoers configuration" explicitly disallows the root access.

How to exploit

What's more interesting is that this flaw can be exploited by an attacker to run commands as root just by specifying the user ID "-1" or "4294967295."

That's because the function which converts user id into its username incorrectly treats -1, or its unsigned equivalent 4294967295, as 0, which is always the user ID of root user.

Affected Sudo versions

The vulnerability affects all Sudo versions prior to the latest released version 1.8.28, which has been released today, a few hours ago and would soon be rolled out as an update by various Linux distributions to their users.

Conclusion

Never take security for granted, even the most important programs that are intended to secure your system may contain security vulnerabilities.

Always keep all your devices up to date, and by the way... What are you waiting for to update your Linux system?

Ok you can take the time to share this and give it a like, but after you must update your Linux system ;)

💖 💪 🙅 🚩
exadra37
Paulo Renato

Posted on October 15, 2019

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