CVE-2024-52508
📋 TL;DR
This vulnerability in Nextcloud Mail allows email account setup details to be sent to attacker-controlled servers when auto-configuration fails. Attackers can register domains like autoconfig.tld to intercept sensitive email credentials. All Nextcloud Mail users with vulnerable versions are affected.
💻 Affected Systems
- Nextcloud Mail
📦 What is this software?
Mail by Nextcloud
Mail by Nextcloud
Mail by Nextcloud
Mail by Nextcloud
Mail by Nextcloud
⚠️ Risk & Real-World Impact
Worst Case
Email credentials and account details are exfiltrated to attacker-controlled servers, potentially leading to full email account compromise and further attacks.
Likely Case
Email credentials are leaked to attackers who have registered malicious autoconfig domains, enabling unauthorized email access.
If Mitigated
With proper patching, no data leakage occurs during email account setup.
🎯 Exploit Status
Exploitation requires attacker to register malicious autoconfig domains and user to attempt email setup.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.14.6, 1.15.4, 2.2.11, 3.6.3, 3.7.7, or 4.0.0
Vendor Advisory: https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vmhx-hwph-q6mc
Restart Required: Yes
Instructions:
1. Update Nextcloud Mail app via Nextcloud app store or manual installation. 2. Restart Nextcloud service. 3. Verify version in Nextcloud admin interface.
🔧 Temporary Workarounds
Disable email account setup
allTemporarily prevent users from setting up new email accounts
Use trusted email providers
allOnly allow email setup with providers known to have proper auto-configuration
🧯 If You Can't Patch
- Monitor for suspicious autoconfig domain registrations targeting your email domains
- Implement network monitoring for connections to unknown autoconfig servers during email setup
🔍 How to Verify
Check if Vulnerable:
Check Nextcloud Mail app version in Nextcloud admin interface under Apps sectionCheck Version:
Check via Nextcloud web interface: Settings → Apps → MailVerify Fix Applied:
Verify version is 1.14.6, 1.15.4, 2.2.11, 3.6.3, 3.7.7, or 4.0.0 or higher📡 Detection & Monitoring
Log Indicators:
- Failed email account setup attempts
- Connections to unusual autoconfig domains
Network Indicators:
- Outbound connections to autoconfig.* domains during email setup
SIEM Query:
source="nextcloud" AND ("autoconfig" OR "mail setup") AND (error OR failed)