FreeSWITCH is an open-source software telecommunications platform. From 1.10.0 to 1.11.1, there is a stack-based buffer overflow in  mod_sofia  when processing SIP Contact display names for dialog-event notifications. A peer can establish a dialog containing an excessively long display name and subsequently subscribe to that entity’s dialog events, causing the stored value to overflow a fixed 512-byte stack buffer. Exploitation requires presence management to be enabled, directly or through shared appearance, and normally requires valid profile credentials unless subscription authentication is disabled. The overflow can terminate the FreeSWITCH process and all active calls. This vulnerability is fixed in version 1.11.2.