ZTE, the world's No.4 handset vendor has admitted that one of its mobile phone models sold in the United States contains a vulnerability that researchers say could allow others to control the device, Reuters reports.  

The hole affects ZTE's Score model that runs on Google's Android operating system and was described by one researcher as "highly unusual."

"I've never seen it before," Dmitri Alperovitch, co-founder of cybersecurity firm, CrowdStrike told Reuters, The hole, usually called a backdoor, allows anyone with the hardwired password to access the affected phone, he added.

ZTE had confirmed the vulnerability on the Score phone, but denied it affected other models.

"ZTE is actively working on a security patch and expects to send the update over the air to affected users in the very near future," ZTE said in an emailed statement. "We strongly urge affected users to download and install the patch as soon as it is rolled out to their devices."

ZTE along with another Chinese telecommunications equipment manufacturer, Huawei Technologies have triggered security concerns in the United States over their alleged links with the Chinese government.

Most such concerns have centered on the fear of backdoors or other security vulnerabilities in telecommunications infrastructure equipment rather than in consumer devices.