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 to conduct a buffer overflow attack due to insufficient bounds checking and input sanitization. A successful exploit could allow an attacker to gain access to sensitive information, modify system configuration or execute arbitrary commands within the context of the system.