The ZTE Score M is an Android 2.3.4 (Gingerbread) phone available in the United States on MetroPCS, made by Chinese telecom ZTE Corporation.
There is a setuid-root application at /system/bin/sync_agent that serves no function besides providing a root shell backdoor on the device.
Just give the magic, hard-coded password to get a root shell:
$ sync_agent ztex1609523
Nice backdoor, ZTE.
Goes to show that no one can be trusted these days, and to always second guess yourself when typing in personal information on phones and the web.