The patches cover bugs that affect RealPlayer versions 10 and 11 and RealPlayer Enterprise, a configurable version that is customized for use in corporations.
The vulnerabilities are ranked "highly critical" by tracking firm Secunia. One of the flaws can be exploited to cause a heap-based buffer overflow when processing a malicious Shockwave Flash file (SWF).
The bug is the only of the four that affects RealPlayer for Windows, Mac and Linux platforms.
The other flaws relate to an ActiveX control error, which can cause a heap memory corruption; an unknown local resources error; and an ActiveX error, which can be exploited to launch a stack-based buffer overflow.
RealNetworks, in an advisory, recommends users upgrade their products to the latest version.