Flaw In Sudo Enables Non-Privileged Users To Run Commands As Root

'A vulnerability has been discovered in Sudo -- one of the most important, powerful, and commonly used utilities that comes as a core command installed on almost every UNIX and Linux-based operating system. 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. Sudo, stands for "superuser do," is a system command that allows a user to run applications or commands with the privileges of a different user without switching environments -- most often, for running commands as the root user. The vulnerability, tracked as CVE-2019-14287 and discovered by Joe Vennix of Apple Information Security, is more concerning because the sudo utility has been designed to let users use their own login password to execute commands as a different user without requiring their password. 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. The vulnerability affects all Sudo versions prior to the latest released version 1.8.28, which has been released today.' -- source: https://linux.slashdot.org/story/19/10/14/2231235 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

On Tue, 15 Oct 2019 13:32:26 +1300, Peter Reutemann quoted:
'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.'
Which, it should be pointed out, is a rather unusual way to use sudo. More commonly it is used to allow selected non-root users to run things as root. More details here <https://www.theregister.co.uk/2019/10/14/linux_sudo_security_bug/>.
participants (2)
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Lawrence D'Oliveiro
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Peter Reutemann