> MSV-4628: Mediatek Baseband NULL Dereference in sdp_msg_pack_media Leading to Denial of Service

An attacker sending a malformed SIP message over VoLTE to a device with a Mediatek baseband can trigger the vulnerability described here. The impact is DoS in the baseband, triggered by malformed VoLTE message such as SIP INVITE or MESSAGE request. The vulnerability described in this advisory affected a wide range of Mediatek devices. This vulnerability is assigned CVE-2025-20725. Vulnerability Details Crash happens due to a NULL access. void sdp_msg_create_negotiation_sdp(...) { sdp_cpy = sdp_msg_struct_copy(sdp_msg); // [1] if (sdp_cpy == (sdp_message_struct *)0x0) { ... return; } media = sdp_cpy->m; if (media != (sdp_media_struct *)0x0) { media_orig_p = sdp_msg->m; // original media while (media_orig_p !