int vnc_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
{
    int n = 0;

    switch(vs->vnc_encoding) {
        case VNC_ENCODING_ZLIB:
            n = vnc_zlib_send_framebuffer_update(vs, x, y, w, h);
            break;
        case VNC_ENCODING_HEXTILE:
            vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_HEXTILE);
            n = vnc_hextile_send_framebuffer_update(vs, x, y, w, h);
            break;
        case VNC_ENCODING_TIGHT:
            n = vnc_tight_send_framebuffer_update(vs, x, y, w, h);
            break;
        case VNC_ENCODING_TIGHT_PNG:
            n = vnc_tight_png_send_framebuffer_update(vs, x, y, w, h);
            break;
        case VNC_ENCODING_ZRLE:
            n = vnc_zrle_send_framebuffer_update(vs, x, y, w, h);
            break;
        case VNC_ENCODING_ZYWRLE:
            n = vnc_zywrle_send_framebuffer_update(vs, x, y, w, h);
            break;
        default:
            vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_RAW);
            n = vnc_raw_send_framebuffer_update(vs, x, y, w, h);
            break;
    }
    return n;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.