CVE-2024-49394
📋 TL;DR
This vulnerability in mutt and neomutt email clients allows attackers to reuse signed but unencrypted email messages by manipulating the In-Reply-To header, enabling sender impersonation. It affects users who rely on cryptographic signing for email authenticity but don't encrypt all messages. The risk is limited to email clients using these specific MUA implementations.
💻 Affected Systems
- mutt
- neomutt
📦 What is this software?
Mutt by Mutt
Neomutt by Neomutt
⚠️ Risk & Real-World Impact
Worst Case
An attacker successfully impersonates a trusted sender in a signed email thread, leading to social engineering attacks, misinformation propagation, or unauthorized actions based on forged communications.
Likely Case
Limited sender impersonation in specific email threads where attackers can intercept and modify signed but unencrypted messages, potentially causing confusion or minor trust violations.
If Mitigated
Minimal impact if organizations enforce full email encryption or use alternative email clients with proper header protection.
🎯 Exploit Status
Requires ability to intercept and modify email messages in transit. Exploitation depends on specific email workflow patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check distribution-specific updates (e.g., mutt 2.2.14+, neomutt 20240301+)
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2024-49394
Restart Required: No
Instructions:
1. Check your distribution's security advisories. 2. Update mutt/neomutt packages using your package manager. 3. Verify the update applied successfully.
🔧 Temporary Workarounds
Enable full email encryption
linuxConfigure mutt/neomutt to always encrypt emails when using cryptographic signing
Add 'set crypt_autoencrypt = yes' to .muttrc
Disable cryptographic signing
linuxTemporarily disable signing until patched (reduces security but eliminates vulnerability)
Add 'set crypt_autosign = no' to .muttrc
🧯 If You Can't Patch
- Switch to alternative email clients with proper header protection
- Implement email gateway filtering to detect suspicious In-Reply-To header manipulation
🔍 How to Verify
Check if Vulnerable:
Check mutt/neomutt version and compare against patched versions for your distributionCheck Version:
mutt -v | head -1Verify Fix Applied:
Verify updated version number and test that In-Reply-To headers are now included in signature verification📡 Detection & Monitoring
Log Indicators:
- Unusual email header modifications in mail server logs
- Signature verification failures for previously valid signed messages
Network Indicators:
- Email messages with modified In-Reply-To headers in transit
SIEM Query:
Not typically applicable as this is client-side vulnerability