“If you use Linux, you are highly recommended to update sudo package manually to the latest version as soon as it is available,” the Sudo Group advised. Sudo can be updated manually by those who do not get an update from their distribution of choice. Sudo Group said most major Linux distributions will do so. The patch does have to be inserted into various distributions to be updated. The good news is that the vulnerability has been patched in Sudo version 1.8.28. “This can be used by a user with sufficient sudo privileges to run commands as root even if the Runas specification explicitly disallows root access as long as the ALL keyword is listed first in the Runas specification,” according to the Sudo vulnerability alert. Using a negative user ID, such as -1, as in -u#-1, triggers the vulnerability and gives root access. In this case, the vulnerability stems from how Sudo treats user IDs. Unlike Microsoft Corp.’s Windows operating system, Linux is most considered to be far more safe from hacking, buy it’s not without its faults. As The Hacker News described it Monday, the sudo security policy bypass issue allows “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.” The vulnerability allows users to bypass the nonroot restriction by simply using -u#-1 in the command line. Details: Exploiting the bug requires that the user have sudo privileges that allow them to run commands with an arbitrary user ID. The vulnerability, known as CVE-2019-14287, does require a nonstandard configuration but nonetheless does open the door to unauthorized users. The tool /TH3xACE/SUDOKILLER allow you to detect the CVE-2019-14287 and also propose how to exploit it. CVE ID: This vulnerability has been assigned CVE-2019-14287 in the Common Vulnerabilities and Exposures database. It’s highly recommended to update the newly released Sudo 1.8.28 version in your Linux and soon the update will be rolled out for all the Linux distributions.Sudo, the main command in Linux that allows users to run tasks, has been found to have a vulnerability that allows unauthorized users to execute commands as a root user. The vulnerability affected only sudoers entries where Runas specifier with ALL keyword and the vulnerability has been assigned CVE-2019-14287 However, due to the bug, bob is actually able to run vi as root by running sudo -u#-1 vi, violating the security policy. User bob is allowed to run vi as any user but root. Linux users urge to update sudo package to the latest version as soon as it is available. “So If a sudoers entry is written to allow the user to run a command as any user except root, the bug can be used to avoid this restriction,” Joe Vennix from Apple Information Security said.Īccording to Sudo report, For example, given the following sudoers entry: The CVE-2019-14287 vulnerability was discovered by Joe Vennix of Apple Information Security, it affects Sudo versions prior to 1.8.28. In this case, when we treat user ID -1 or 4294967295 (unsigned equivalent for -1 ), the result returns 0 (Not root). In the above command with (ALL) in Runas Specifier, a user can run the command as any users, also able to run it as an arbitrary user ID by using the #uid syntax. To exploit the bug, the users should have Sudo privilege, which means, the user’s entry in Runas specifier with special value ALL, so that users can run a command as an arbitrary user. Runas basically referred to allow a Linux user to start an application with different user credentials, and it restricts the users to gain other privileged access.īased on the Sudo users policy, If ALL keyword in a Runas specification, then any user to run commands as an arbitrary user.īy exploiting the vulnerability in Sudo let normal users with sufficient Sudo privileges to run commands as root even if the Runas specification explicitly disallows root access and allows to gain the complete control of the system. Falco allows users to filter and detect this kind of activity by writing a custom rule to match the exploit behaviour pattern, to then alert regarding the. The vulnerability affected the Sudo versions before 1.8.28 and the potential users to bypass the Runas user restrictions. CVE-2019-14287 vulnerability allows malicious users to exploit locally certain sudoers configurations that allow to run commands as other unprivileged users to run any command as root. Sudo (Superuser Do) program in Linux is responsible to allocate the security privileges to run commands for normal users and by default for Superusers. A new vulnerability has been discovered in the Linux Sudo program let unprivileged users can run the command as root by specifying the user ID -1 or 4294967295.
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