In Realtek eCos RSDK 1.5.7p1 and MSDK 4.9.4p1, the SIP ALG function that rewrites SDP data has a stack-based buffer overflow. This allows an attacker to remotely execute code without authentication via a crafted SIP packet that contains malicious SDP data.
https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2022-27255.pdf