FreeRDP from 3.14.1 before 3.32.0 contains an integer underflow in the WinPR BMP writer, where a mismatched stride calculation passes SIZE_MAX - 3 to Stream_Zero for sub-byte images. A malicious RDP clipboard peer can return a crafted 1-bpp BMP processed by clipboard_synthesize_image_format_to_bmp for CF_DIB/CF_DIBV5, crashing the client or causing an out-of-bounds write.