A vulnerability on Mitel 6800 Series and 6900 Series SIP Phones through 6.3 SP3 HF4, 6900w Series SIP Phone through 6.3.3, and 6970 Conference Unit through 5.1.1 SP8 allows an authenticated attacker with administrative privilege to conduct an argument injection attack due to insufficient parameter sanitization. A successful exploit could allow an attacker to access sensitive information, modify system configuration or execute arbitrary commands.
https://www.mitel.com/support/security-advisories/mitel-product-security-advisory-24-0009