Description

The Tauri HTTP plugin validates requested URLs against the application's configured scope allowlist only once, on the initial request. When the remote server responds with an HTTP 3xx redirect, reqwest follows the redirect internally without re-checking the new target URL against the scope. This allows an attacker who controls an allowed URL (or finds an open redirect on an allowed host) to reach disallowed destinations such as cloud metadata endpoints, localhost services, or internal network hosts.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.6",
  "pubDate": "2026-09-22T11:17:27.357Z",
  "pubdate": "2026-09-22T11:17:27.357Z",
  "executiveSummary": "The Tauri HTTP plugin contains a critical security vulnerability involving improper validation of redirected HTTP requests. The vulnerability is classified as a scope bypass flaw where security checks are performed only during the initial request phase.\nWhen the reqwest library, utilized by the Tauri HTTP plugin, processes an HTTP 3xx redirect, it follows the new Location header internally without re-validating the destination against the user-configured scope allowlist.\nThis flaw allows a remote attacker to bypass defined security boundaries, enabling access to sensitive internal network resources, local services, or cloud metadata endpoints that should be restricted.\nThe impact is significant, as it permits Server-Side Request Forgery (SSRF) patterns facilitated by trusted hosts that either contain open redirects or are under the control of an adversary.\nExploitation requires the attacker to influence the initial request target to an allowed host that redirects to a restricted resource. No specific authentication is required to trigger this vulnerability, making it a high-risk vector for environments relying on scoped network access for Tauri applications.",
  "technicalDetails": "The root cause of this vulnerability lies in the insufficient enforcement of the security scope policy within the Tauri HTTP plugin's request lifecycle management. The application configures an allowlist intended to restrict outgoing network requests to specific domains or patterns. However, the plugin performs validation solely at the entry point of the HTTP request process.\nThe underlying implementation utilizes the reqwest library, which provides transparent redirect handling. When the server returns a 3xx status code (e.g., 301 Moved Permanently or 302 Found), reqwest automatically processes the redirect by issuing a subsequent request to the URI specified in the Location header. Because the Tauri HTTP plugin fails to intercept or re-verify this secondary request against the predefined scope configuration, the check is bypassed entirely.\nAn attacker can exploit this via a two-stage process. First, the attacker identifies or hosts a domain that is currently present in the application's allowlist. Second, the attacker configures this host to return an HTTP 3xx redirect to a sensitive, disallowed target. Targets include loopback interfaces (e.g., 127.0.0.1), private CIDR blocks representing internal microservices, or cloud-specific metadata services such as 169.254.169.254.\nThe attack flow proceeds as follows: 1) The Tauri application initiates an HTTP request to the allowed, attacker-controlled (or compromised) origin. 2) The plugin verifies the initial URL against the scope and permits the request. 3) The server returns a 3xx response containing the URL of the internal target. 4) The reqwest client transparently follows this redirect to the restricted destination. 5) The server's response from the restricted resource is returned to the Tauri application, potentially leaking sensitive information or allowing the attacker to perform unauthorized actions against internal services.\nThis vulnerability is particularly dangerous in desktop environments where Tauri applications may have access to local hardware interfaces or local API endpoints that assume the requester is a trusted internal component. The failure to re-validate the target URL during redirect handling effectively negates the security guarantees provided by the scope allowlist, allowing for arbitrary egress control bypass."
}