A security flaw in Microsoft’s Azure cloud discovered by Tenable Vulnerability Assessment Team researchers allows bad actors to bypass firewall rules and access private web resources of other Azure customers. The issue stems from service tags in Azure that group IP addresses used by Azure services. Tenable warns that a rogue Azure customer could exploit this vulnerability to conduct cross-tenant attacks on other customers who rely on service tags in their firewall rules.
Microsoft initially dismissed the problem as a misunderstanding but later acknowledged it as a “privilege elevation flaw.” Microsoft paid Tenable a bug bounty but did not release a patch to fix the issue. Instead, Microsoft recommends customers take a multi-layered security approach and review their use of service tags.
Tenable published a technical description of the issue and a proof-of-concept scenario using Azure App Services. The vulnerability affects at least 10 other Azure services, including Application Insights, DevOps, and Machine Learning. Microsoft did not release a patch but issued an “improved guide” for Azure service tags documentation.
Both Microsoft and Tenable emphasize the importance of addressing security gaps to protect user safety. Microsoft recommends adding authentication and authorization checks to prevent exploitation of the vulnerability. It is crucial for customers to implement multiple layers of security controls to safeguard valuable resources and data.
Article Source
https://www.theregister.com/AMP/2024/06/05/tenable_azure_flaw/