CVE-2024-54662: Dante SOCKS Server Auth Bypass Flaw

CVE-2024-54662 Overview

CVE-2024-54662 is a critical access control vulnerability affecting Dante, a widely-used SOCKS proxy implementation. The vulnerability exists in Dante versions 1.4.0 through 1.4.3 and has been fixed in version 1.4.4. The flaw stems from incorrect access control enforcement in certain sockd.conf configurations involving the socksmethod directive, potentially allowing unauthorized network access through the proxy server.

Critical Impact
Attackers can exploit misconfigured Dante proxy servers to bypass authentication and access control mechanisms, potentially gaining unauthorized network access with high confidentiality and integrity impact.

Affected Products

Dante versions 1.4.0 through 1.4.3
Systems running vulnerable Dante SOCKS proxy configurations
Network environments relying on socksmethod authentication in sockd.conf

Discovery Timeline

2024-12-16 - Inet releases security advisory detailing the vulnerability
2024-12-17 - CVE-2024-54662 published to NVD
2024-12-18 - Last updated in NVD database

Technical Details for CVE-2024-54662

Vulnerability Analysis

This vulnerability is classified under CWE-863 (Incorrect Authorization), indicating that the Dante SOCKS proxy fails to properly enforce access control policies under specific configuration scenarios. When certain socksmethod settings are configured in sockd.conf, the proxy incorrectly processes authorization checks, allowing connections that should otherwise be denied.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring authentication or user interaction. Successful exploitation can result in unauthorized access to protected network resources and the ability to modify or intercept network traffic passing through the compromised proxy.

Root Cause

The root cause lies in the improper handling of authentication method configurations within the Dante daemon (sockd). When specific combinations of socksmethod directives are present in the configuration file, the access control logic fails to correctly validate client permissions, creating a bypass condition. This represents a flaw in the authorization decision-making process that should restrict connections based on the configured authentication requirements.

Attack Vector

The attack vector is network-based, requiring the attacker to have network access to the vulnerable Dante proxy server. Exploitation does not require authentication, privileges, or user interaction. An attacker can craft SOCKS connection requests that exploit the misconfigured access control logic, bypassing the intended authentication requirements and gaining unauthorized proxy access.

The vulnerability specifically affects configurations where socksmethod is used to define authentication requirements. When the authorization checks are bypassed, attackers can utilize the proxy to:

Access internal network resources that should be protected
Route malicious traffic through the compromised proxy
Potentially intercept or modify data passing through the proxy

Detection Methods for CVE-2024-54662

Indicators of Compromise

Unexpected or unauthorized SOCKS connections originating from external sources
Unusual traffic patterns through the Dante proxy from unrecognized clients
Authentication bypass attempts visible in proxy logs when authentication should be required

Detection Strategies

Review sockd.conf configuration files for vulnerable socksmethod configurations
Monitor Dante proxy logs for connections that bypass expected authentication mechanisms
Implement network monitoring to detect anomalous proxy usage patterns
Conduct configuration audits to identify affected Dante installations

Monitoring Recommendations

Enable verbose logging in Dante to capture connection authentication details
Implement alerting for connections from unexpected source IP addresses
Monitor for sudden increases in proxy traffic volume that may indicate exploitation
Deploy network intrusion detection signatures for SOCKS protocol anomalies

How to Mitigate CVE-2024-54662

Immediate Actions Required

Upgrade Dante to version 1.4.4 or later immediately
Review and audit all sockd.conf configurations for socksmethod directives
Restrict network access to Dante proxy servers using firewall rules
Monitor proxy logs for signs of unauthorized access

Patch Information

Inet has released Dante version 1.4.4 which addresses this access control vulnerability. Organizations should upgrade to this patched version as soon as possible. The official security advisory is available at the Inet Security Advisory 2024-12-16 page. Additional product documentation can be found at the Dante Proxy Documentation site.

Workarounds

Implement network-level access controls (firewalls, ACLs) to restrict who can connect to the Dante proxy
Review and strengthen socksmethod configurations to ensure proper authentication is enforced
Consider temporarily disabling the Dante proxy if immediate patching is not possible
Deploy additional authentication layers such as VPN requirements for proxy access

bash

# Verify Dante version and upgrade if vulnerable
sockd -v
# If version shows 1.4.0-1.4.3, upgrade immediately

# Restrict proxy access at the firewall level
iptables -A INPUT -p tcp --dport 1080 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 1080 -j DROP