CVE-2022-50927: Cyclades Server Privilege Escalation Flaw

CVE-2022-50927 Overview

CVE-2022-50927 is a local privilege escalation vulnerability affecting Cyclades Serial Console Server version 3.3.0. The vulnerability stems from overly permissive sudo privileges configured for the admin user and admin group. Attackers with local access can exploit the default user configuration to gain root access by manipulating system binaries and leveraging unrestricted sudo permissions.

Critical Impact

Local attackers can escalate privileges to root, gaining complete control over the affected serial console server and potentially compromising connected infrastructure.

Affected Products

• Cyclades Serial Console Server 3.3.0

Discovery Timeline

• 2026-01-13 - CVE CVE-2022-50927 published to NVD
• 2026-01-13 - Last updated in NVD database

Technical Details for CVE-2022-50927

Vulnerability Analysis

This privilege escalation vulnerability is classified under CWE-266 (Incorrect Privilege Assignment). The flaw exists in how the Cyclades Serial Console Server configures sudo privileges for administrative users. The default configuration grants the admin user and admin group unrestricted access to execute commands as root without proper constraints or command whitelisting.

The vulnerability requires local access to the system, meaning an attacker must first obtain credentials or shell access to the device. Once authenticated as a member of the admin group, the attacker can leverage the permissive sudo configuration to execute arbitrary commands with root privileges.

Serial console servers are critical infrastructure components often used to manage network equipment, servers, and other devices out-of-band. Compromising such a device could provide attackers with access to management interfaces of numerous connected systems.

Root Cause

The root cause of CVE-2022-50927 is improper privilege assignment in the sudo configuration. The admin user and admin group are granted excessive permissions that allow them to execute any command as root without adequate restrictions. This violates the principle of least privilege and creates a direct path from a low-privilege administrative account to full root access.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have existing access to the system. An attacker with valid credentials for an admin-level account can exploit the misconfigured sudo privileges to escalate their access to root. This can be accomplished by:

1. Authenticating to the system as an admin user
2. Exploiting the unrestricted sudo permissions to execute privileged commands
3. Manipulating system binaries or configurations to establish persistent root access

Technical details and exploitation methods are documented in the Exploit-DB #50773 entry and the VulnCheck Advisory.

Detection Methods for CVE-2022-50927

Indicators of Compromise

• Unexpected sudo command executions by admin users, especially those targeting sensitive binaries
• Modified system files or binaries that should be static
• Unusual user privilege escalation events in authentication logs
• Creation of new root-level accounts or modifications to /etc/passwd and /etc/shadow

Detection Strategies

• Monitor /var/log/auth.log and /var/log/secure for sudo usage patterns by admin accounts
• Implement file integrity monitoring on critical system binaries and configuration files
• Alert on any modifications to the sudoers configuration file
• Review authentication logs for anomalous admin account activity

Monitoring Recommendations

• Deploy SentinelOne agents where possible to detect privilege escalation attempts and suspicious process execution
• Configure centralized logging to aggregate sudo and authentication events from serial console servers
• Establish baseline admin user behavior and alert on deviations
• Implement network segmentation to limit access to management interfaces

How to Mitigate CVE-2022-50927

Immediate Actions Required

• Review and restrict sudo privileges for the admin user and admin group to only necessary commands
• Audit existing admin accounts and remove any unnecessary privileged access
• Implement strong authentication mechanisms including multi-factor authentication where supported
• Isolate serial console servers on dedicated management networks with strict access controls

Patch Information

Check with Vertiv (the vendor) for firmware updates that address this vulnerability. Review the VulnCheck Advisory for the latest mitigation guidance.

Workarounds

• Modify the sudoers configuration to implement command whitelisting instead of unrestricted access
• Remove unnecessary users from the admin group
• Consider replacing affected devices with updated hardware that includes patched firmware
• Implement network-level access controls to limit who can authenticate to the device

# Example: Restrict sudo access to specific commands only
# Edit /etc/sudoers using visudo
# Replace unrestricted admin access with explicit command whitelisting:
# admin ALL=(ALL) NOPASSWD: /usr/bin/specific_command, /usr/sbin/another_command