CVE-2022-23124: Netatalk Information Disclosure Flaw

CVE-2022-23124 Overview

CVE-2022-23124 is an out-of-bounds read vulnerability affecting Netatalk, an open-source AFP (Apple Filing Protocol) fileserver implementation. This vulnerability allows remote attackers to disclose sensitive information on affected installations without requiring authentication. The specific flaw exists within the get_finderinfo method, where improper validation of user-supplied data can result in a read past the end of an allocated buffer. When combined with other vulnerabilities, an attacker can leverage this flaw to execute arbitrary code in the context of root.

Critical Impact

Unauthenticated remote attackers can exploit this vulnerability to disclose sensitive information and potentially achieve root-level code execution when chained with other vulnerabilities.

Affected Products

• Netatalk (all versions prior to 3.1.13)
• Debian Linux 10.0
• Debian Linux 11.0

Discovery Timeline

• March 28, 2023 - CVE CVE-2022-23124 published to NVD
• November 4, 2025 - Last updated in NVD database

Technical Details for CVE-2022-23124

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), a memory corruption flaw that occurs when software reads data past the boundary of an allocated buffer. In the context of Netatalk, the get_finderinfo method fails to properly validate the length of user-supplied data before processing it, allowing attackers to read memory contents beyond the intended buffer boundaries.

The vulnerability is particularly dangerous because it does not require authentication to exploit. Netatalk's AFP implementation processes incoming network requests, and malicious input can trigger the out-of-bounds read condition. While the primary impact is information disclosure, the leaked memory contents could reveal sensitive data including credentials, session tokens, or memory layout information useful for further exploitation.

When chained with other vulnerabilities in the Netatalk software, this information disclosure primitive can facilitate arbitrary code execution with root privileges, as Netatalk services typically run with elevated permissions to manage file shares.

Root Cause

The root cause of CVE-2022-23124 lies in insufficient bounds checking within the get_finderinfo method. The function processes Finder metadata information in AFP requests but fails to validate that user-supplied length parameters fall within the bounds of the allocated buffer. This allows an attacker to specify a length value that exceeds the actual buffer size, causing the software to read and potentially return memory contents beyond the intended data structure.

Attack Vector

The attack vector for CVE-2022-23124 is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Connecting to a vulnerable Netatalk AFP service over the network
2. Sending specially crafted AFP requests targeting the get_finderinfo method
3. Including malicious length parameters that exceed buffer boundaries
4. Receiving sensitive memory contents in the server's response

The vulnerability is tracked by Zero Day Initiative as ZDI-CAN-15870 and published as ZDI-22-525. The exploitation does not require complex conditions or timing, making it relatively straightforward to exploit remotely.

Detection Methods for CVE-2022-23124

Indicators of Compromise

• Unusual AFP service activity or connection patterns from unknown sources
• Abnormal memory access patterns or crashes in Netatalk processes
• Unexpected network traffic on AFP ports (typically TCP port 548)
• Log entries indicating malformed AFP requests to the Netatalk service

Detection Strategies

• Monitor Netatalk service logs for suspicious connection attempts and malformed requests
• Deploy network intrusion detection rules to identify anomalous AFP protocol traffic
• Implement memory monitoring to detect out-of-bounds access attempts
• Use SentinelOne Singularity Platform to detect exploitation attempts and memory corruption behaviors

Monitoring Recommendations

• Enable verbose logging for the Netatalk service to capture detailed request information
• Monitor system resource usage for signs of information exfiltration
• Implement network segmentation to limit exposure of AFP services
• Deploy endpoint detection and response (EDR) solutions capable of detecting memory-based attacks

How to Mitigate CVE-2022-23124

Immediate Actions Required

• Update Netatalk to version 3.1.13 or later immediately
• Restrict network access to AFP services to trusted networks only
• Monitor exposed Netatalk instances for signs of exploitation attempts
• Review and apply security patches for Debian systems using the DSA-5503 advisory

Patch Information

Netatalk has released version 3.1.13 which addresses this vulnerability. Organizations should consult the Netatalk Release Notes for detailed upgrade instructions. Debian users should apply the patches documented in DSA-5503 and Debian LTS Announcement. Gentoo users should reference GLSA 202311-02. Additional guidance is available from CERT Vulnerability Report 709991.

Workarounds

• Disable Netatalk services if AFP functionality is not required
• Implement firewall rules to block external access to TCP port 548
• Deploy network-level filtering to restrict AFP protocol access to authorized clients only
• Consider using alternative file sharing protocols until patching is complete

# Example firewall configuration to restrict AFP access
# Block external access to Netatalk AFP service (port 548)
iptables -A INPUT -p tcp --dport 548 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 548 -j DROP

# Or disable the Netatalk service temporarily
systemctl stop netatalk
systemctl disable netatalk