CVE-2024-45626
📋 TL;DR
Apache James server versions below 3.7.6 and 3.8.2 have a vulnerability in their JMAP HTML-to-text conversion implementation that allows attackers to cause unbounded memory consumption, leading to denial of service. This affects all Apache James server deployments using vulnerable versions with JMAP enabled. The vulnerability can be exploited remotely by sending specially crafted HTML content through JMAP.
💻 Affected Systems
- Apache James Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage of Apache James server due to memory exhaustion, potentially affecting all email and messaging services running on the server.
Likely Case
Degraded performance or temporary service disruption as the server consumes excessive memory processing malicious HTML content.
If Mitigated
Minimal impact with proper monitoring and resource limits in place, though some performance degradation may still occur.
🎯 Exploit Status
Exploitation requires sending HTML content through JMAP protocol. No authentication bypass is mentioned in the advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.7.6 or 3.8.2
Vendor Advisory: https://lists.apache.org/thread/1fr9hvpsylomwwfr3rv82g84sxszn4kl
Restart Required: Yes
Instructions:
1. Download Apache James 3.7.6 or 3.8.2 from official Apache repository. 2. Stop the current James server. 3. Backup configuration files. 4. Install the new version. 5. Restore configuration if needed. 6. Start the upgraded server.
🔧 Temporary Workarounds
Disable JMAP Protocol
allTemporarily disable JMAP protocol to prevent exploitation while planning upgrade
Edit james-server.xml and set <jmap.enabled>false</jmap.enabled>
Restart Apache James service
Implement Memory Limits
linuxSet strict memory limits for Apache James process to contain memory consumption
Set JVM heap limits: -Xmx2g -Xms1g
Configure OS-level memory limits using ulimit or systemd
🧯 If You Can't Patch
- Implement strict network filtering to limit JMAP access to trusted sources only
- Deploy monitoring with alerts for abnormal memory consumption patterns
🔍 How to Verify
Check if Vulnerable:
Check Apache James version: grep 'james.version' in configuration files or check server startup logsCheck Version:
java -jar james-server.jar --version or check logs/startup.logVerify Fix Applied:
Verify version is 3.7.6 or higher (for 3.7.x branch) or 3.8.2 or higher (for 3.8.x branch)📡 Detection & Monitoring
Log Indicators:
- Unusual memory consumption patterns in JMAP logs
- OutOfMemoryError exceptions in server logs
- High memory usage alerts from monitoring
Network Indicators:
- Unusually large HTML content being sent via JMAP protocol
- Multiple JMAP requests with HTML attachments from single source
SIEM Query:
source="apache-james" AND ("OutOfMemory" OR "memory" AND "high" OR "exhausted")