dbcve.org
Expo Software Development KitApplication · Expo

CVE-2023-28131

CRITICAL · 9.6 CVSS v3.1 Published 2023-04-24
Fix available
A fix is available. Upgrade to 48.0.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the expo.io framework allows an attacker to take over accounts and steal credentials on an application/website that configured the "Expo AuthSession Redirect Proxy" for social sign-in. This can be achieved once a victim clicks a malicious link. The link itself may be sent to the victim in various ways (including email, text message, an attacker-controlled website, etc).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is an open redirect vulnerability in Expo's AuthSession Redirect Proxy. When applications configure this proxy for social sign-in, the proxy fails to properly validate redirect URLs, allowing attackers to craft malicious links that redirect authenticated users to attacker-controlled sites after the OAuth flow completes, enabling account takeover and credential theft.

MitigationDisable or reconfigure the Expo AuthSession Redirect Proxy to only allow whitelisted redirect URLs, and implement strict URL validation to prevent arbitrary redirect targets during the OAuth authentication flow.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Expo Software Development KitApplication
Affected:>= 45.0.0, < 48.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Expo SDK version in use
    Run `expo --version` or check your package.json for the `@expo/sdk` or `expo` package version. If using bare React Native, check the `expo` and `expo-modules-core` versions in node_modules.
    Affected if The installed Expo SDK version is 45.0.0, 45.0.1, 45.0.2, 45.0.3, 45.0.4, 45.0.5, 45.0.6, 45.0.7, 45.0.8, 45.0.9, 45.1.0, 45.1.1, 45.1.2, 46.0.0, 46.1.0, 46.2.0, 46.3.0, 46.4.0, 46.5.0, 46.6.0, 46.7.0, 47.0.0, 47.1.0, 47.2.0, 47.3.0, or 47.4.0.
  2. Confirm AuthSession is being used
    Search your codebase for imports of `expo-auth-session` or `AuthSession` from the expo modules. Check for usage of `makeRedirectUri` and `useAuthRequest` hooks.
    Affected if Your application imports and uses the expo-auth-session module for OAuth authentication.
  3. Verify Redirect Proxy is enabled
    Check your app.json or app.config.js for the `extra.authSessionRedirectUri` property, or look for environment variables or code that sets `AuthSession.makeRedirectUri({ proxy: true })`. Also check if your app uses the default Expo proxy domain (auth.expo.io) in redirect URIs.
    Affected if The AuthSession is configured to use the Expo redirect proxy (proxy: true in makeRedirectUri, or your redirect URIs contain 'auth.expo.io').
  4. Inspect redirect URL validation
    Review your OAuth configuration where you define `shouldHandleCallback` or where you process the callback URL. Look for how the `returnTo` or `redirectUri` parameter is validated after the OAuth flow completes.
    Affected if Your code does not strictly validate that the redirect URL matches an exact whitelist of allowed domains before redirecting the user.

You are affected if your application runs on Expo SDK 45.0.0 through 47.4.0, uses expo-auth-session with the redirect proxy enabled, and lacks strict whitelist validation on callback redirect URLs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 48.0.0 or later
Fixed in 48.0.0
Interim mitigation

Disable or reconfigure the Expo AuthSession Redirect Proxy to only allow whitelisted redirect URLs, and implement strict URL validation to prevent arbitrary redirect targets during the OAuth authentication flow.

Recommended fix High confidence

Expo SDK 48.0.0 or later

  1. Upgrade your Expo SDK from version 45.0.0-47.x to version 48.0.0 or later
  2. Run 'npx expo install --fix' or manually update expo package.json dependencies to SDK 48
  3. Run 'npm install' or 'yarn install' to install the updated dependencies
  4. Test your application's authentication flow to verify the fix is working correctly
  5. Ensure your build environment uses the updated SDK version for production builds
Caveat Expo SDK 48 may include breaking changes; review the Expo SDK 48 release notes for any migration requirements related to authentication, navigation, or other affected modules.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Expo Software Development Kit Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-28131 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-28131 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data