Abuse of shared key authorizations, a default on Azure storage accounts, could allow a threat actor to steal higher privileged access tokens, move laterally throughout the network, and execute remote code, aka RCE.
Researchers at Orca were able to demonstrate how an attacker could breach Microsoft Storage Accounts, but Microsoft's Security Response Center (MSRC) chalked it up to a misconfiguration rather than a vulnerability. MRSC did offer guidance to users to appropriately configure Azure Functions and "effectively deploy environments with the least privilege." The company said it is planning to address the issue as part of its regular "experience improvements."
Orca researchers urge IT teams to take the issue seriously, and added that even though Microsoft doesn't consider the potential privilege escalation a vulnerability, "This does not mean that it is less dangerous," Orca's report said. "Actually, it should be considered even more dangerous since there is no straightforward 'fix'."
Administrators are advised by Microsoft to:
- Review user permissions to ensure least-privilege access
- Monitor logs for account key access
- Consider using a storage account dedicated to application code blob storage
- Enable Microsoft Defender for Cloud (MDC) on storage accounts