Vulnérabilités dans les séries Cisco Expressway et Cisco TelePresence Video Communication Server

The impact of CVE-2022-20754 is severe. Successful exploitation allows an attacker to gain root access to the Cisco Expressway device, effectively granting them complete control over the system. This includes the ability to modify system configurations, install malicious software, steal sensitive data, and potentially pivot to other systems on the network. Given the critical nature of the vulnerability and the potential for remote code execution, this represents a significant security risk. The ability to write files allows for persistence and the potential to establish a backdoor for future access. This vulnerability shares similarities with other privilege escalation exploits where attackers leverage application vulnerabilities to gain root access.

Organizations heavily reliant on Cisco TelePresence VCS Expressway for video conferencing and collaboration are at significant risk. This includes large enterprises, educational institutions, and government agencies. Specifically, deployments with weak password policies or overly permissive access controls to the Expressway management interfaces are particularly vulnerable. Shared hosting environments utilizing Cisco Expressway are also at increased risk due to the potential for cross-tenant exploitation.

• linux / server:

journalctl -u expressway | grep -i "error" -i "exception"

• cisco:

show running-config | grep -i expressway

• generic web:

curl -I https://<expressway_ip>/admin/api/v1/  # Check for exposed API endpoints

1. 2022-04-06Disclosure

   disclosure

1. Réservé2021-11-02
2. Publiée2022-04-06
3. Modifiée2024-11-06
4. EPSS mis à jour2026-04-02

Due to the lack of a specified 'fixed_in' version, immediate mitigation strategies are crucial. Cisco recommends reviewing the advisory for potential workarounds and configuration changes that may limit the attack surface. Implement strict access controls to the Expressway management interfaces, limiting access to only authorized personnel. Consider using a Web Application Firewall (WAF) to filter malicious requests targeting the vulnerable APIs. Monitor system logs for suspicious activity, particularly attempts to write files or execute commands. Regularly audit user accounts and permissions to ensure least privilege access is enforced. After applying any configuration changes or implementing WAF rules, verify the effectiveness by attempting to reproduce the vulnerability in a test environment.