Description

Improper restriction of communication channel to intended endpoints in Azure SQL Managed Instance allows an unauthorized attacker to elevate privileges over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.7",
  "pubDate": "2026-08-07T00:16:34.727Z",
  "pubdate": "2026-08-07T00:16:34.727Z",
  "executiveSummary": "An improper restriction of communication channel vulnerability exists within Azure SQL Managed Instance. This security flaw enables an unauthorized network-based attacker to elevate privileges within the affected environment.\nThe vulnerability affects Azure SQL Managed Instance deployments where communication channels lack sufficient hardening or endpoint restriction enforcement. By exploiting this flaw, a malicious actor operating over the network can bypass standard access controls to execute unauthorized administrative actions or escalate their privilege level.\nThe risk implications are severe, as successful exploitation compromises the confidentiality, integrity, and availability of the database service and potentially underlying host resources.\nAttack capabilities require network access to the targeted Azure SQL Managed Instance communication channels, leveraging the improper endpoint restrictions to inject or relay traffic that precipitates privilege escalation.\nNo specific authentication requirements are mandated for the initial network-based vector if the channel itself is exposed to unauthorized entities, highlighting the critical nature of boundary enforcement in cloud-hosted database environments.",
  "technicalDetails": "The root cause of this vulnerability stems from an improper restriction of communication channels to intended endpoints within the Azure SQL Managed Instance architecture. Specifically, the underlying network listener or inter-process communication mechanism fails to adequately validate or restrict the origin and destination of channel traffic, allowing unauthorized entities to interact with sensitive management or data services.\nThe vulnerable component is the communication channel management subsystem responsible for handling network connections and internal service endpoints in Azure SQL Managed Instance.\nExploitation occurs over a network vector. Because the communication channel is improperly restricted, an unauthorized attacker positioned on the network can establish unauthorized connections or manipulate existing channel data streams.\nThe attack flow proceeds as follows: First, the attacker identifies the exposed or insufficiently restricted communication channel endpoints associated with the Azure SQL Managed Instance. Second, the attacker transmits crafted payloads or initiates unauthorized protocol commands across the network interface. Third, due to the lack of strict endpoint validation, the system processes these inputs as coming from a trusted or authorized internal source. Finally, the processing of these unauthorized commands results in the elevation of the attacker's privileges, granting them unauthorized access levels.\nPrivilege requirements for the initial access phase are minimal or non-existent from an authenticated perspective if the channel is exposed, while the post-exploitation impact culminates in elevated privileges allowing administrative control over the targeted database instance.\nNetwork exposure is a primary prerequisite, as the flaw is exploitable over the network by actors capable of reaching the misconfigured or improperly restricted communication endpoints."
}