Description

Improper neutralization of input during web page generation ('cross-site scripting') in Azure Portal allows an unauthorized attacker to perform spoofing over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.2",
  "pubDate": "2026-09-18T00:17:44.960Z",
  "pubdate": "2026-09-18T00:17:44.960Z",
  "executiveSummary": "This vulnerability is classified as Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting (XSS). The flaw resides within the Azure Portal environment, where insufficient input sanitization allows for the injection of arbitrary client-side scripts.\nThe primary impact of this vulnerability is the potential for unauthorized attackers to perform spoofing attacks over a network. By injecting malicious scripts into the web interface, an attacker can manipulate the content rendered to legitimate users, potentially deceiving them into disclosing sensitive information or performing unintended actions.\nThe vulnerability affects the Azure Portal platform. Given the high-trust environment of Azure management consoles, this flaw poses a significant risk to organizational security, as it allows attackers to bypass standard UI trust boundaries. Successful exploitation requires network access and the ability to influence input vectors processed by the portal, which are subsequently rendered in the victim's browser session. No authentication is inherently required to initiate a spoofing attempt if the input vector is externally reachable, though the impact is realized upon the interaction of an authenticated user with the tainted content.",
  "technicalDetails": "The root cause of this vulnerability is the failure of the Azure Portal application to adequately neutralize untrusted user-supplied data before incorporating it into the Document Object Model (DOM) of the rendered web page. When the application accepts input that is subsequently reflected back to a user without proper contextual encoding or validation, the browser interprets the input as executable code rather than plain text.\nIn a typical Cross-Site Scripting attack flow within the Azure Portal, the attacker identifies an input field, URL parameter, or header that is not properly sanitized. The attacker crafts a malicious payload—typically containing JavaScript—designed to manipulate the page content, redirect the user, or hijack session data. This payload is delivered to the victim, often through a crafted link or via persistent storage if the application saves the malicious input to a database.\nUpon the victim's browser loading the affected page, the injected JavaScript executes within the security context of the Azure Portal. Because the browser treats the script as originating from the legitimate, trusted origin of the Azure Portal, it bypasses Same-Origin Policy (SOP) restrictions that would otherwise prevent cross-site interactions. In this specific scenario, the execution of the script allows the attacker to perform 'spoofing'—the visual or functional alteration of the UI—enabling the attacker to display fraudulent elements, such as fake login prompts or deceptive system messages designed to elicit unauthorized user behavior.\nThe vulnerability is characterized by a failure in output encoding. To achieve successful exploitation, the attacker must bypass existing filtering mechanisms, if any are present, by utilizing obfuscation techniques or leveraging character encoding discrepancies that the application's sanitization logic fails to recognize. The impact is escalated in cloud environments where the portal acts as the centralized control plane for critical infrastructure, meaning a spoofing attack could theoretically be chained with other techniques to perform account takeover or unauthorized resource modification if user session tokens are accessible via the execution context."
}