Description

HCL AION is affected by a vulnerability where the X-Content-Type-Options header was missing or insecure, allowing browsers to MIME-sniff responses. This may cause content to be interpreted as an unintended type, potentially resulting in unintended behavior or security impact under certain conditions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "3.7",
  "pubDate": "2026-11-06T13:17:30.453Z",
  "pubdate": "2026-11-06T13:17:30.453Z",
  "executiveSummary": "HCL AION suffers from a security misconfiguration involving the omission or insecure implementation of the X-Content-Type-Options HTTP response header. This vulnerability exposes the application to MIME-sniffing, a browser-based behavior where the client attempts to 'guess' the MIME type of a response rather than strictly adhering to the declared Content-Type header.\nThe vulnerability primarily impacts HCL AION by allowing attackers to bypass Content-Type protections, potentially leading to Cross-Site Scripting (XSS) or the execution of malicious scripts disguised as benign files (e.g., images or text files).\nAn attacker can exploit this by uploading or hosting malicious files that the browser will interpret as executable script content when served by the application. This does not require prior authentication in all scenarios, as it relies on the browser's response handling logic rather than the server's internal access controls.\nThe risk implication is significant, as it facilitates the injection of arbitrary client-side code, which could lead to session hijacking, unauthorized actions on behalf of the user, or sensitive information disclosure. Organizations utilizing HCL AION must ensure that security headers are strictly enforced to prevent the browser from deviating from the intended MIME type.",
  "technicalDetails": "The root cause of this vulnerability is the failure of the HCL AION web server configuration to include the 'X-Content-Type-Options: nosniff' HTTP response header. When this header is absent or improperly configured, web browsers—specifically those with MIME-sniffing capabilities—attempt to analyze the byte stream of a file or response to determine its content type, even if the server explicitly provides a Content-Type header. This behavior is intended to improve user experience for legacy web pages, but it poses a severe security risk in modern application environments.\nThe attack flow commences when an attacker identifies a vector to upload or reference content through HCL AION that is ostensibly non-executable (e.g., a file disguised as an image or a static text file). Because the X-Content-Type-Options header is missing, the browser, upon receiving the file, inspects the payload content. If the content contains characters that resemble HTML or JavaScript, the browser may 'sniff' the content and override the server-supplied Content-Type (e.g., text/plain) to interpret the file as text/html or application/javascript.\nOnce the browser re-categorizes the file as an executable format, it will process and execute any embedded JavaScript within the user's session context. This bypasses the protections typically afforded by MIME-type restrictions, as the browser essentially trusts the 'sniffed' content type over the server's declared intent. This is particularly dangerous when HCL AION serves user-uploaded content or dynamically generated responses that an attacker can influence.\nExploitation does not necessarily require the attacker to have high-level privileges; rather, it requires that the attacker be able to influence content hosted on or served by the HCL AION instance. Once the script is executed, the impact is standard for reflected or stored XSS, including the potential to access Document Object Model (DOM) data, exfiltrate session cookies via document.cookie, perform unauthorized API requests as the authenticated user, or redirect users to malicious domains. The vulnerability is fundamentally a failure to restrict the browser’s interpretive autonomy, thereby undermining the integrity of content delivery mechanisms within the HCL AION product."
}