CVE-2022-0730: Cacti Authentication Bypass Vulnerability

CVE-2022-0730 Overview

CVE-2022-0730 is an authentication bypass vulnerability affecting Cacti, a widely-used open-source network monitoring and graphing solution. Under certain LDAP conditions, an attacker can bypass Cacti's authentication mechanism using specific credential types, potentially gaining unauthorized access to the monitoring infrastructure without valid credentials.

Critical Impact

This authentication bypass vulnerability allows unauthenticated attackers to gain complete access to Cacti installations configured with LDAP authentication, potentially compromising network monitoring infrastructure and exposing sensitive operational data.

Affected Products

• Cacti version 1.2.19 and potentially earlier versions
• Debian Linux versions 9.0, 10.0, and 11.0
• Fedora versions 34, 35, and 36

Discovery Timeline

• March 3, 2022 - CVE-2022-0730 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-0730

Vulnerability Analysis

This vulnerability is classified as CWE-287 (Improper Authentication), indicating a fundamental flaw in how Cacti validates user credentials when LDAP authentication is configured. The vulnerability exists in the authentication logic that processes LDAP bind operations, where certain credential types are not properly validated before granting access.

When Cacti is configured to use LDAP for user authentication, the application performs bind operations against the LDAP directory to verify user credentials. The flaw allows attackers to craft specific credential payloads that the vulnerable authentication logic incorrectly accepts as valid, bypassing the intended authentication controls entirely.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any prior authentication or user interaction, making it particularly dangerous for internet-facing Cacti deployments.

Root Cause

The root cause of CVE-2022-0730 lies in improper handling of LDAP authentication responses within Cacti's authentication subsystem. The vulnerability stems from insufficient validation of certain credential types during the LDAP bind process. When specific conditions are met in the LDAP configuration, the authentication check fails to properly distinguish between successful and unsuccessful authentication attempts, allowing malformed or empty credentials to be treated as valid.

Attack Vector

The attack vector for CVE-2022-0730 is network-based, requiring no privileges or user interaction. An attacker targeting a vulnerable Cacti installation can:

1. Identify Cacti instances using LDAP authentication through reconnaissance
2. Submit specially crafted authentication requests with specific credential types
3. Exploit the improper validation to bypass authentication checks
4. Gain unauthorized access to the Cacti web interface with elevated privileges

The exploitation does not require complex techniques and can be performed directly against the Cacti web authentication endpoint. Once authenticated, attackers can access sensitive network monitoring data, modify configurations, or use the compromised system as a pivot point for further attacks.

Detection Methods for CVE-2022-0730

Indicators of Compromise

• Unusual authentication success events in Cacti logs without corresponding valid LDAP bind confirmations
• Multiple rapid authentication attempts from single IP addresses targeting the Cacti login endpoint
• Access to administrative functions from unexpected user accounts or IP ranges
• Anomalous LDAP traffic patterns between Cacti and the directory server

Detection Strategies

• Monitor Cacti authentication logs for successful logins that lack associated LDAP server confirmation
• Implement network-level monitoring for unusual patterns in LDAP bind request traffic
• Deploy web application firewall rules to detect malformed authentication requests
• Review Cacti access logs for administrative actions from unauthorized or anomalous sessions

Monitoring Recommendations

• Enable verbose LDAP logging on both Cacti and the LDAP directory server to correlate authentication events
• Configure SIEM alerts for authentication anomalies including credential-less successful authentications
• Implement network traffic analysis to detect exploitation attempts against the Cacti authentication endpoint
• Regularly audit user sessions and administrative activities within Cacti for unauthorized access

How to Mitigate CVE-2022-0730

Immediate Actions Required

• Update Cacti to the latest patched version that addresses CVE-2022-0730
• Review LDAP authentication configurations and restrict LDAP access to known trusted sources
• Implement network segmentation to limit exposure of Cacti instances to untrusted networks
• Audit recent authentication logs for potential signs of exploitation

Patch Information

Patches for this vulnerability are available through the official Cacti project and major Linux distributions. For detailed patch information and updates, refer to the Cacti GitHub Issue #4562 which tracks this vulnerability. Distribution-specific patches are available through:

• Debian Security Advisory DSA-5298
• Debian LTS Security Announcement
• Fedora Package Announcements for versions 34, 35, and 36

Workarounds

• If patching is not immediately possible, consider temporarily disabling LDAP authentication and using local authentication
• Restrict network access to the Cacti web interface using firewall rules to limit exposure
• Implement additional authentication layers such as VPN requirements or IP whitelisting for Cacti access
• Monitor and alert on all authentication events until the patch can be applied

# Example: Restrict Cacti access using iptables
# Allow only specific trusted networks to access Cacti
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP