CVE-2015-8314
📋 TL;DR
This vulnerability in the Devise authentication gem for Ruby allows attackers to forge 'Remember Me' cookies, potentially gaining unauthorized persistent access to user accounts. It affects Ruby applications using Devise for authentication with the 'rememberable' module enabled. The issue stems from improper handling of cookie signatures.
💻 Affected Systems
- Devise Ruby gem
📦 What is this software?
Devise by Heartcombo
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain persistent administrative access to applications, leading to complete system compromise, data theft, and privilege escalation.
Likely Case
Attackers gain unauthorized access to user accounts, potentially accessing sensitive data and performing actions as legitimate users.
If Mitigated
With proper session management and monitoring, impact is limited to temporary account access that can be detected and revoked.
🎯 Exploit Status
Exploitation requires access to valid user sessions or ability to forge cookies. The vulnerability is well-documented in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.5.4 and later
Vendor Advisory: https://github.com/advisories/GHSA-746g-3gfp-hfhw
Restart Required: Yes
Instructions:
1. Update Gemfile to 'gem "devise", ">= 3.5.4"' 2. Run 'bundle update devise' 3. Restart application server 4. Invalidate all existing remember me tokens by resetting secret_key_base
🔧 Temporary Workarounds
Disable Remember Me feature
allTemporarily disable the rememberable module in Devise configuration
# In config/initializers/devise.rb
# Remove or comment out :rememberable from devise modules
Rotate secret_key_base
allChange the Rails secret_key_base to invalidate all existing cookies
# In config/secrets.yml
# Change secret_key_base value and restart application
🧯 If You Can't Patch
- Implement additional session validation and monitoring
- Deploy WAF rules to detect cookie manipulation attempts
🔍 How to Verify
Check if Vulnerable:
Check Gemfile.lock for devise version: 'grep devise Gemfile.lock' and verify version is < 3.5.4Check Version:
bundle show devise | grep -o 'devise-[0-9.]*'Verify Fix Applied:
Confirm devise version is >= 3.5.4 in Gemfile.lock and test remember me functionality📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts with remember me tokens
- Unusual session durations or locations
Network Indicators:
- Suspicious cookie manipulation in HTTP requests
SIEM Query:
source="application.log" AND ("remember_me" OR "rememberable") AND ("failed" OR "invalid")🔗 References
- https://github.com/advisories/GHSA-746g-3gfp-hfhw
- https://github.com/heartcombo/devise/commit/c92996646aba2d25b2c3e235fe0c4f1a84b70d24
- https://rubysec.com/advisories/CVE-2015-8314/
- https://github.com/advisories/GHSA-746g-3gfp-hfhw
- https://github.com/heartcombo/devise/commit/c92996646aba2d25b2c3e235fe0c4f1a84b70d24
- https://rubysec.com/advisories/CVE-2015-8314/
