CVE-2025-57821
📋 TL;DR
This vulnerability in Basecamp's Google Sign-In gem allows attackers to craft URLs that bypass same-origin checks, potentially redirecting users to malicious sites. Rails applications using this gem with session cookie storage are affected. The risk is elevated when combined with session cookie injection attacks.
💻 Affected Systems
- Basecamp Google Sign-In gem for Rails
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could redirect authenticated users to malicious sites, potentially leading to session hijacking, credential theft, or further exploitation through chained attacks.
Likely Case
Limited impact requiring specific conditions - attacker needs to chain this with session cookie injection and user interaction, making successful exploitation less common.
If Mitigated
With proper SameSite cookie settings, the attack surface is significantly reduced as session cookies won't be sent in cross-site requests.
🎯 Exploit Status
Exploitation requires chaining with session cookie injection vulnerability and user interaction with crafted URL.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3.0
Vendor Advisory: https://github.com/basecamp/google_sign_in/security/advisories/GHSA-7pwc-wh6m-44q3
Restart Required: No
Instructions:
1. Update Gemfile to specify 'gem "google_sign_in", ">= 1.3.0"' 2. Run 'bundle update google_sign_in' 3. Deploy updated application
🔧 Temporary Workarounds
Set SameSite cookie attribute
allConfigure Rails session cookies with SameSite=Lax or SameSite=Strict to prevent cross-site request forgery attacks
# In config/application.rb or config/environments/production.rb
# Rails.application.config.session_store :cookie_store, same_site: :lax
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) to restrict redirect destinations
- Add additional validation for redirect URLs in application code
🔍 How to Verify
Check if Vulnerable:
Check Gemfile.lock for google_sign_in version less than 1.3.0Check Version:
grep google_sign_in Gemfile.lockVerify Fix Applied:
Verify Gemfile.lock shows google_sign_in version 1.3.0 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual redirect patterns in application logs
- Multiple failed authentication attempts with crafted URLs
Network Indicators:
- Unexpected cross-origin redirects from authentication endpoints
SIEM Query:
web_redirects WHERE dest_domain NOT IN (allowed_domains) AND src_path CONTAINS '/auth/google'