URL spoofing via unsanitized forwarded-host port
Published Apr 1, 2025 · Updated Apr 2, 2025
URL spoofing in the Express adapter for React Router 7.0.0 through 7.4.0 allows remote attackers to alter the incoming Request URL. The adapter splits Host or X-Forwarded-Host at a colon, treats the unsanitized suffix as a port, and concatenates it with req.hostname and req.originalUrl to construct the URL. Applications using the Express adapter can route a request to an attacker-chosen path, enabling path-control bypasses or cache poisoning and service interruption when a shared cache stores the response.
Summary
What happened
URL spoofing in the Express adapter for React Router 7.0.0 through 7.4.0 allows remote attackers to alter the incoming Request URL. The adapter splits Host or X-Forwarded-Host at a colon, treats the unsanitized suffix as a port, and concatenates it with req.hostname and req.originalUrl to construct the URL. Applications using the Express adapter can route a request to an attacker-chosen path, enabling path-control bypasses or cache poisoning and service interruption when a shared cache stores the response.
The record
- CVE
- CVE-2025-31137
- Published
- Apr 1, 2025
- Updated
- Apr 2, 2025
- Vendor
- Shopify
- Product
- React Router
- Classifications
- CWE-444, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 1, 2025CVE publishedPublication date reported by the CVE source.
- Apr 2, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 2.11.1, < 2.16.3
- Affected versionversion=>= 7.0.0, < 7.4.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- React Router and the Remix’ed path demonstrationsfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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