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CVSS Score
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Technical Details
Vulnerability Intelligence
Miggo AI
Miggo AIMiggo AIMiggo AIRoot Cause AnalysisThe analysis of the vulnerability in the x402 SDK started by examining the provided security advisory, which indicated that versions prior to 0.5.2 were affected. By comparing the git tags for a vulnerable version (v0.5.1) and a patched version (v0.5.3), I identified a set of commits that were introduced between these releases. Among these, the commit 35ed8cabfecbf1d47af0b9cab4048da7e05256c1 with the message 'fix: expanded route logic to handle encoded uri segments' stood out as the likely security patch.
An in-depth look at this commit revealed changes in typescript/packages/x402/src/shared/middleware.ts, specifically within the findMatchingRoute function. The core of the patch is the introduction of decodeURIComponent to process the request path before it is matched against the application's routes. Previously, the lack of decoding meant that URL-encoded characters were not interpreted correctly, creating a loophole for bypassing path-based security controls. The corresponding test file, middleware.test.ts, was also updated with numerous tests for URL-encoded paths, confirming the nature of the fix.
The root cause of the vulnerability is improper input handling, where the application trusted the request path without proper sanitization and normalization (in this case, decoding). This could lead to an authorization bypass. For a security engineer, this means that any resource server using an affected version of the x402 SDK could be vulnerable to having its route-based access controls bypassed, potentially exposing sensitive endpoints.
| Package Name | Ecosystem | Vulnerable Versions | First Patched Version |
|---|---|---|---|
| x402 | npm | < 0.5.2 | 0.5.2 |
| x402-next | npm | < 0.5.2 | 0.5.2 |
| x402-express | npm | < 0.5.2 | 0.5.2 |
| x402-hono | npm | < 0.5.2 | 0.5.2 |