Description

Unauthenticated Cross Site Scripting (XSS) in SmartSMTP <= 1.2.0 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.1",
  "pubDate": "2026-08-20T12:16:34.317Z",
  "pubdate": "2026-08-20T12:16:34.317Z",
  "executiveSummary": "This vulnerability is an Unauthenticated Cross-Site Scripting (XSS) security flaw affecting the SmartSMTP plugin in versions 1.2.0 and below.\nThe primary impact of this vulnerability is the execution of arbitrary malicious JavaScript in the context of a victim's browser session, which can lead to session hijacking, credential theft, and unauthorized administrative actions if targeted against privileged users.\nThe affected product is SmartSMTP versions <= 1.2.0, presenting significant risk implications for web applications utilizing the vulnerable component due to the lack of required authentication or user interaction constraints beyond tricking a user into executing the payload.\nThe attacker capabilities include delivering and triggering malicious scripts remotely without requiring prior authentication or valid credentials.\nExploitation requirements are minimal, relying on network accessibility to the vulnerable endpoint and the injection of crafted malicious payloads that bypass insufficient input sanitization and output encoding mechanisms.",
  "technicalDetails": "The root cause of the vulnerability stems from inadequate input validation and improper output encoding of user-supplied data handled by the SmartSMTP plugin.\nThe vulnerable component processes HTTP requests containing parameters that are subsequently reflected back into the Hypertext Markup Language (HTML) response without sufficient sanitization, allowing the injection of arbitrary script tags or event handlers.\nThe affected versions include SmartSMTP <= 1.2.0, with network exposure directly affecting any web server hosting the vulnerable plugin instance.\nRegarding authentication and privilege requirements, the vulnerability is explicitly unauthenticated, meaning no valid user session or privileges are required by the threat actor to initiate the attack vector.\nThe attack flow proceeds as follows: First, the attacker crafts a malicious Uniform Resource Locator (URL) or Hypertext Transfer Protocol (HTTP) request containing an embedded Cross-Site Scripting payload (such as JavaScript code within script tags or event attributes). Second, the attacker induces an unauthenticated or authenticated user to interact with the crafted link or resource via network exposure. Third, the application processes the incoming request and reflects the unsanitized input directly into the Document Object Model (DOM) of the resulting web page without applying appropriate context-aware output encoding. Fourth, the victim's browser parses the HTTP response and executes the injected payload in the security context of the victim's current session.\nThe payload behavior involves executing arbitrary JavaScript code within the victim's browser, which can interact with the Document Object Model, access session cookies, steal authentication tokens, or perform unauthorized state-changing requests on behalf of the user.\nThe post-exploitation impact includes potential account compromise, unauthorized administrative privilege escalation if an administrator views the payload, and unauthorized data access within the application scope."
}