CVE-2023-31096 — Out-of-bounds Write in LSI Pci-sv92ex Firmware

An issue was discovered in Broadcom) LSI PCI-SV92EX Soft Modem Kernel Driver through 2.2.100.1 (aka AGRSM64.sys). There is Local Privilege Escalation to SYSTEM via a Stack Overflow in RTLCopyMemory (IOCTL 0x1b2150). An attacker can exploit this to elevate privileges from a medium-integrity process to SYSTEM. This can also be used to bypass kernel-level protections such as AV or PPL, because exploit code runs with high-integrity privileges and can be used in coordinated BYOVD (bring your own vuln…