Original URL: http://www.theregister.co.uk/2009/06/11/china_censorware_security_holes/

Security holes poked in Chinese compulsory PC filter plan

Green Dam it all

By John Leyden

Posted in Security, 11th June 2009 10:14 GMT

Plans to mandate the use of a particular brand of censorware software in China pose a grave security risk, security watchers and net privacy activists warn.

All PCs shipped to China from July 1 2009 onwards will be required to bundle a locally brewed application called Green Dam Youth Escort in order to prevent access to "harmful content". The parental control/censorship software, developed by Jinhui Computer System Engineering, will be used to block access to porn as well as politically sensitive content, in conjunction with server-side and ISP-level filters (the so-called Great Firewall of China) already in place.

By creating a software monoculture the Chinese authorities are creating a risk that a vulnerability in the software, providing it was serious enough to allow remote code injection, could be used to create a huge botnet. More subtle flaws might also be used to create targeted attacks on government computers - a factor that is unlikely to pass unnoticed down at the NSA.

And the whole exercise might be of limited use anyway, because early versions of the software work only IE or Google Chrome on Windows. According to collaborative tests, carried out in China and summarised by Global Voices here, the software fails to work with Firefox. The software - already widely deployed in China - is incompatible with Mac or Linux machines.

Other reported problems include suggestions that the Green Dam Youth Escort is a resource hog, might be high maintenance when it comes to applying upgrades, and has been found to inadvertently block course-related material in schools.

Questions are also being asked about the costs of the software, estimated as costing 41m Yuan in the first year.

Isaac Mao, a research fellow at Harvard University's Berkman Center for Internet and Society, has uncovered other problems with the software. Communications between the systems at Jinhui and client PC running its Green Dam Youth Escort are unencrypted, leaving the door open for man in the middle attacks and clickstream snooping. It could be the system is designed this way to allow the Chinese government to monitor its citizens.

However, Green Dam maintains that its software is "only a filter", the BBC (citing reports in the official Chinese media last year) reports. ®