Microsoft Azure VMs exploited to infect users with botnet malware

Cloud Security
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Unsurprisingly, threat actors have started actively exploiting the critical Azure (opens in new tab) vulnerabilities, not long after they were publicly disclosed and patched by Microsoft in the recent September Patch Tuesday (opens in new tab) release.

BleepingComputer reports that the first attacks were spotted last week by security researcher Germán Fernández (opens in new tab), before being confirmed by cybersecurity (opens in new tab) vendors GreyNoise (opens in new tab) and Bad Packets (opens in new tab).

The four privilege escalation and remote code execution vulnerabilities were discovered (opens in new tab) in the Open Management Infrastructure (OMI) software agent, which is automatically deployed inside Linux (opens in new tab) virtual machines (VM (opens in new tab)) when users enable certain Azure services.

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However, in a surprising move, instead of patching all affected Azure services, Microsoft instead released an advisory (opens in new tab) stating that while it’ll update six of them, seven others must be updated by users themselves.

Capitalizing on laxity

The OMI vulnerabilities were discovered by researchers at Wiz, who estimate that they affect thousands of Azure customers, across millions of endpoints. 

"With a single packet, an attacker can become root on a remote machine by simply removing the authentication header. It’s that simple," shared Wiz researcher Nir Ohfeld, adding that one of the four vulnerabilities (tracked as CVE-2021-38647) could be exploited to target Azure.

No wonder then, GreyNoise is already tracking (opens in new tab) attackers scanning the internet for exposed Azure Linux VMs vulnerable to CVE-2021-38647 exploits.

Other security researchers, such as Kevin Beaumont have already had their vulnerable honeypots compromised (opens in new tab) with cryptominers (opens in new tab).

In a bizarre twist, while Microsoft has patched the vulnerabilities, the company shared that it’s still in the process of rolling out the update for some of the compromisable services to its cloud customers.

“Customers must update vulnerable extensions for their Cloud and On-Premises deployments as the updates become available per schedule outlined in table below...” read Microsoft’s advisory - much to the chagrin of security researchers.

Via BleepingComputer (opens in new tab)

With almost two decades of writing and reporting on Linux, Mayank Sharma would like everyone to think he’s TechRadar Pro’s expert on the topic. Of course, he’s just as interested in other computing topics, particularly cybersecurity, cloud, containers, and coding.