CVE-2024-55414
smserl64.sys — physical memory mapping in Motorola Soft Modem driver (removed in January 2026 update)
Summary
| Field | Value |
|---|---|
| Driver | smserl64.sys (Motorola Soft Modem) |
| Vulnerability Class | Arbitrary Physical Memory Mapping |
| CVSS | 7.8 |
| Exploited ITW | No |
| Patch Date | January 13, 2026 (driver removed) |
Root Cause
The Motorola Soft Modem driver maps physical memory to user mode with no access control checks. Any local user can read and write arbitrary physical memory through the driver. Microsoft removed the legacy driver in the January 2026 update.
Exploitation
The attacker opens a handle to the driver device and requests physical memory mappings. Direct physical memory R/W provides a complete kernel compromise primitive.
Exploitation Primitive
Open device handle → request physical memory mapping
→ arbitrary physical memory R/W → kernel compromise
(mitigated by driver removal)