CVE-2025-34099 is an OS command injection vulnerability classified under CWE-78 and CWE-20 that affects VICIdial Group's VICIdial software versions 2.9 RC1 through 2.13 RC1. The vulnerability exists in the vicidial_sales_viewer.php script when password encryption is enabled—a non-default configuration. The root cause is the insecure handling of the HTTP Basic Authentication password, which is passed directly to the PHP exec() function without proper input validation or sanitization. This allows an unauthenticated remote attacker to inject arbitrary shell commands, which the web server executes with its privileges. Since the vulnerability requires no authentication or user interaction, exploitation is straightforward, increasing the risk. The exec() function is inherently dangerous when handling user input, and the lack of sanitization violates secure coding practices. Although the vulnerability was mitigated in 2017, legacy systems that have not applied patches remain vulnerable. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N) indicates network attack vector, low complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. No known exploits are currently reported in the wild, but the critical nature of the flaw demands immediate attention.

For European organizations, especially those operating call centers or customer support platforms using VICIdial, this vulnerability poses a severe risk. Exploitation can lead to full system compromise, allowing attackers to execute arbitrary commands, potentially leading to data exfiltration, service disruption, or pivoting within the network. Confidential customer data, call logs, and sensitive operational information could be exposed or manipulated. The availability of the VICIdial system could be compromised, impacting business continuity and customer service operations. Given the unauthenticated nature of the exploit, attackers can launch attacks remotely without prior access, increasing the threat landscape. The impact is heightened in regulated industries such as finance, healthcare, and telecommunications, where data protection and service availability are critical. Additionally, the vulnerability could be leveraged for ransomware deployment or lateral movement within corporate networks.

1. Immediately upgrade VICIdial installations to versions later than 2.13 RC1 where this vulnerability has been mitigated. 2. If upgrading is not immediately possible, disable password encryption in the vicidial_sales_viewer.php component to avoid the vulnerable code path. 3. Implement strict input validation and sanitization on all user-supplied inputs, especially those passed to system-level commands. 4. Restrict web server user privileges to the minimum necessary to limit the impact of potential command execution. 5. Monitor network traffic and logs for unusual or suspicious activity related to the vicidial_sales_viewer.php endpoint. 6. Employ web application firewalls (WAFs) with custom rules to detect and block command injection attempts targeting this component. 7. Conduct regular vulnerability scans and penetration tests focusing on legacy VICIdial deployments. 8. Educate IT staff about the risks of enabling non-default configurations like password encryption without proper security review. 9. Maintain an incident response plan to quickly address potential exploitation attempts.