Attackers are increasingly targeting a remote code execution vulnerability in the Open Management Infrastructure (OMI) framework that Microsoft released patches for earlier this month.
Dubbed OMIGOD and tracked as CVE-2021-38647, this critical vulnerability was found to affect the Linux virtual machines deployed on Azure. In addition to fixes released with its September 2021 Patch Tuesday updates, Microsoft last week released additional mitigations for this bug and three elevation of privilege flaws impacting OMI.
Microsoft says that Azure customers with automatic updates enabled should receive the necessary fixes within days, while others should manually update their installations. Other Linux distributions that have the Azure/SCOM/OMS agents installed are also at risk, Pwndefend says.
Security researcher Kevin Beaumont, however, warns that Microsoft failed to apply the patches for new deployments, and that the manner in which the tech giant approached the delivery of patches is not as straightforward as expected.
Unsurprisingly, less than a week after the vulnerability was publicly disclosed (Microsoft actually pushed fixes to the OMI source code on August 12), attacks targeting CVE-2021-38647 are ramping up.
This is what usually happens when critical, highly impactful security defects are made public, but things seem especially grim for this bug in particular, because exploitation is rather trivial.
“Rather than guessing a valid authentication token to insert into a fraudulent OMI web request, you simply omit all mention of the authentication token altogether, and you’re in,” Sophos explains.
The good news is that there aren’t as many Internet-facing vulnerable deployments as has recently happened with similar vulnerabilities. According to Censys, there are 101 known exposed services worldwide potentially at risk, which includes a major health entity and two major entertainment organizations.
“The small footprint can be associated with nuances of how the OMI service responds, and that exposing OMI to the Internet likely requires deliberate effort,” Censys points out.
Security researchers monitoring the activity surrounding OMIGOD warn of an increasing number of exploitation attempts targeting the bug.
Microsoft too has observed the behavior, saying it ranges from host enumeration to attacks aimed at installing cryptocurrency miners or other types of malware. The tech giant is also aware of reports that cybercriminals have exploited the flaw to install a Mirai variant.
“While many of the attackers are looking for port 5986, we are also seeing attacks on port 1270. Due to the number of easily adaptable proof of concept exploits available and the volume of reconnaissance-type attacks, we are anticipating an increase in the number of effects-type attacks,” the company says.
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