CVE-2024-42010
📋 TL;DR
This vulnerability in Roundcube webmail allows remote attackers to exfiltrate sensitive information from rendered email messages due to insufficient CSS filtering. Attackers can craft malicious CSS in emails to steal data when victims view those emails. All Roundcube users running affected versions are at risk.
💻 Affected Systems
- Roundcube Webmail
⚠️ 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
Complete compromise of email contents including sensitive attachments, credentials, and confidential communications through CSS-based data exfiltration.
Likely Case
Targeted information theft where attackers send specially crafted emails to harvest specific data from victims' email sessions.
If Mitigated
Limited impact with proper email filtering and user awareness, but still potential for data leakage from malicious emails that bypass filters.
🎯 Exploit Status
Exploitation requires sending malicious emails to victims who then view them in Roundcube. No authentication needed to send emails, but victim interaction required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Roundcube 1.5.8 or 1.6.8
Vendor Advisory: https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8
Restart Required: No
Instructions:
1. Backup your Roundcube installation and database. 2. Download the patched version (1.5.8 or 1.6.8) from GitHub releases. 3. Replace the existing Roundcube files with the patched version. 4. Clear browser caches and test functionality.
🔧 Temporary Workarounds
Disable HTML email rendering
allConfigure Roundcube to display emails as plain text only, preventing CSS execution
Edit config/config.inc.php and set: $config['prefer_html'] = false;
$config['show_images'] = 0;
Disable mod_css_styles
allTurn off CSS processing in email rendering
Edit config/config.inc.php and set: $config['css_styles'] = false;
🧯 If You Can't Patch
- Implement strict email filtering to block emails with suspicious CSS content
- Educate users to avoid opening emails from unknown senders and to use plain text mode
🔍 How to Verify
Check if Vulnerable:
Check Roundcube version in program/include/iniset.php or via Roundcube interfaceCheck Version:
grep -r 'RCMAIL_VERSION' program/include/iniset.phpVerify Fix Applied:
Verify version is 1.5.8 or higher for 1.5.x branch, or 1.6.8 or higher for 1.6.x branch📡 Detection & Monitoring
Log Indicators:
- Unusual email access patterns
- Multiple failed CSS parsing attempts in Roundcube logs
Network Indicators:
- Outbound connections to unusual domains after email viewing
- CSS data exfiltration patterns in network traffic
SIEM Query:
source="roundcube.log" AND ("css" OR "style" OR "token") AND ("error" OR "failed" OR "malformed")🔗 References
- https://github.com/roundcube/roundcubemail/releases
- https://github.com/roundcube/roundcubemail/releases/tag/1.5.8
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.8
- https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8
- https://sonarsource.com/blog/government-emails-at-risk-critical-cross-site-scripting-vulnerability-in-roundcube-webmail/
