CVE-2025-13033
📋 TL;DR
This vulnerability in email parsing libraries allows attackers to redirect emails to external addresses by embedding them within quotes in recipient fields. This affects any application using vulnerable email libraries like nodemailer, potentially exposing sensitive information. Organizations using these libraries for email processing are at risk.
💻 Affected Systems
- nodemailer
⚠️ 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 email system compromise with all outgoing emails redirected to attacker-controlled addresses, leading to massive data exfiltration of sensitive communications, credentials, and confidential information.
Likely Case
Targeted attacks redirecting specific sensitive emails (password resets, financial data, confidential communications) to attacker addresses, enabling data theft and potential account takeover.
If Mitigated
Limited impact with proper email filtering, recipient validation, and monitoring in place, potentially catching redirection attempts before data loss occurs.
🎯 Exploit Status
Exploitation requires ability to submit specially crafted email addresses to vulnerable systems, but no authentication is needed once access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: nodemailer 6.9.15 and later
Vendor Advisory: https://github.com/nodemailer/nodemailer/security/advisories/GHSA-mm7p-fcc7-pg87
Restart Required: Yes
Instructions:
1. Update nodemailer to version 6.9.15 or later using npm update nodemailer. 2. Restart all applications using nodemailer. 3. Verify the update was successful by checking the package.json file.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side validation to reject email addresses containing quotes or suspicious patterns before processing.
Email Recipient Whitelisting
allRestrict email sending to pre-approved internal domains only, blocking external addresses in recipient fields.
🧯 If You Can't Patch
- Implement network segmentation to isolate email processing systems from sensitive data sources
- Deploy email content inspection and DLP solutions to detect and block suspicious email redirections
🔍 How to Verify
Check if Vulnerable:
Check package.json or run npm list nodemailer to see if version is below 6.9.15Check Version:
npm list nodemailer | grep nodemailerVerify Fix Applied:
Confirm nodemailer version is 6.9.15 or higher using npm list nodemailer and test email functionality📡 Detection & Monitoring
Log Indicators:
- Unusual email delivery patterns
- Failed recipient validations
- Emails sent to unexpected external domains
Network Indicators:
- Unexpected SMTP connections to external mail servers
- Unusual outbound email traffic patterns
SIEM Query:
source="email_server" AND (recipient CONTAINS "\"" OR recipient_domain NOT IN ["company.com","trusted-domain.com"])🔗 References
- https://access.redhat.com/errata/RHSA-2026:3751
- https://access.redhat.com/security/cve/CVE-2025-13033
- https://bugzilla.redhat.com/show_bug.cgi?id=2402179
- https://github.com/nodemailer/nodemailer
- https://github.com/nodemailer/nodemailer/commit/1150d99fba77280df2cfb1885c43df23109a8626
- https://github.com/nodemailer/nodemailer/security/advisories/GHSA-mm7p-fcc7-pg87
