The patch closes nine security holes that could allow an attacker to take over a computer running the RealOne Player.
The vulnerabilities, described as "buffer overruns", were first discovered in November. In buffer overrun attacks, malicious hackers can exploit an unchecked buffer in a program to load and run their code on the vulnerable system.
Users would have to be tricked by attackers into downloading a malformed file. RealNetworks said that no exploitations of the security holes have yet been reported. Nevertheless, the company issued a patch for the vulnerabilities in late November.
However, the patch issued by RealNetworks did not solve the reported security problems, and the mix-up prompted RealNetworks to announce a wholesale review of its RealOne Player source code to identify any other vulnerabilities in the product.
Although the results of that audit were not mentioned in a statement from RealNetworks, the nine holes have been plugged.
Individuals using RealOne Player can obtain the update by selecting the Check for Updates option on the RealOne Player's tools menu, or by visiting the RealNetworks Web site and downloading the software patch at http://service.real.com/help/faq/security/bufferoverrun_update.html.