CVE-2024-38439
📋 TL;DR
CVE-2024-38439 is a critical heap-based buffer overflow vulnerability in Netatalk's PAM authentication module. An attacker can exploit this to execute arbitrary code or crash the service, potentially gaining remote code execution. All systems running vulnerable Netatalk versions with PAM authentication enabled are affected.
💻 Affected Systems
- Netatalk
📦 What is this software?
Netatalk by Netatalk
Netatalk by Netatalk
Netatalk by Netatalk
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with root privileges, allowing complete system compromise and lateral movement within the network.
Likely Case
Service crash leading to denial of service, or remote code execution with the privileges of the Netatalk process.
If Mitigated
Denial of service if exploit attempts are blocked or fail, with no code execution.
🎯 Exploit Status
The vulnerability is in the authentication flow, allowing unauthenticated attackers to trigger the buffer overflow during login attempts.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.4.1, 3.1.19, or 3.2.1
Vendor Advisory: https://netatalk.io/security/CVE-2024-38439
Restart Required: Yes
Instructions:
1. Stop Netatalk service. 2. Update to patched version using package manager or compile from source. 3. Restart Netatalk service.
🔧 Temporary Workarounds
Disable PAM authentication
linuxRemove or disable the vulnerable uams_pam.so module from Netatalk configuration
Edit /etc/netatalk/afp.conf and remove 'uams_pam.so' from uams list
Restart netatalk: systemctl restart netatalk
🧯 If You Can't Patch
- Implement network segmentation to isolate Netatalk servers from critical systems
- Deploy intrusion prevention systems (IPS) to detect and block exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check Netatalk version with 'netatalk -v' or 'afpd -v' and compare against affected versionsCheck Version:
netatalk -v 2>/dev/null || afpd -v 2>/dev/null || dpkg -l | grep netatalk || rpm -qa | grep netatalkVerify Fix Applied:
Confirm version is 2.4.1, 3.1.19, or 3.2.1 or higher📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts with malformed credentials
- Netatalk service crashes or restarts
Network Indicators:
- Unusual traffic to Netatalk port 548/tcp (AFP) or 427/udp (SLP)
SIEM Query:
source="netatalk.log" AND ("authentication failed" OR "segmentation fault" OR "buffer overflow")🔗 References
- https://github.com/Netatalk/netatalk/blob/90d91a9ac9a7d6132ab7620d31c8c23400949206/etc/uams/uams_pam.c#L316
- https://github.com/Netatalk/netatalk/issues/1096
- https://github.com/Netatalk/netatalk/security/advisories/GHSA-8r68-857c-4rqc
- https://netatalk.io/security/CVE-2024-38439
- https://github.com/Netatalk/netatalk/blob/90d91a9ac9a7d6132ab7620d31c8c23400949206/etc/uams/uams_pam.c#L316
- https://github.com/Netatalk/netatalk/issues/1096
- https://github.com/Netatalk/netatalk/security/advisories/GHSA-8r68-857c-4rqc
- https://lists.debian.org/debian-lts-announce/2024/11/msg00026.html
- https://netatalk.io/security/CVE-2024-38439
