Minion privilege escalation exploit patched in SaltStack Salt project

The bug permitted attackers to perform privilege escalation attacks in the automation software.

The Salt Project has patched a privilege escalation bug impacting SaltStack Salt minions that could be used during a wider exploit chain. 

The vulnerability, CVE-2020-28243, is described as a privilege escalation bug impacting SaltStack Salt minions allowing "an unprivileged user to create files in any non-blacklisted directory via a command injection in a process name." 

The bug has been given a severity rating of 7.0 and impacts Salt versions before 3002.5.

SaltStack's Salt is an open source project and software designed for automation and infrastructure management. 

In November, Immersive Labs' security researcher Matthew Rollings performed a scan on the tool using Bandit, a Python application security scanner, and came across the bug as a result. 

Salt includes a master system and minions, of which the latter facilitates commands sent to the master, and both often run as root. Rollings discovered a command injection vulnerability in minions when the master system summons a process called restartcheck. Exploits can be triggered if attackers use crafted process names, permitting local users to escalate their privileges on root -- as long as they are able to create files on a minion in a non-forbidden directory. 

With further investigation, the researcher noted it may also be possible to perform container escapes, including performing the exploit "within a container to gain command execution as root on the host machine."

In addition, Rollings said the vulnerability "may be performed by an attacker without local shell access, [and] under certain circumstances, remote users can influence process names." However, this form of attack is considered "unlikely" and could be difficult to trigger. 

The Salt Project resolved the vulnerability in a February security release. The group also patched other high-impact bugs including CVE-2021-3197, a shell injection flaw in Salt-API's SSH client; CVE-2021-25281, an eAuth security issue that could allow remote attackers to run any wheel modules on the master, and CVE-2021-25283, a failure to protect against server-side template injection attacks. 

ZDNet has reached out to the Salt Project and will update when we hear back. 

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