The four vulnerabilities that have been deemed as highly critical refer to the fact that an attacker, from a remote location, could get access to the user's sensitive information. RealNetworks has issued a fix at the end of last week, and all RealPlayer users are well advised to update and patch their vulnerable software. No matter what platform you use, be it Windows, Mac or Linux, at least one vulnerability can affect your system.

The vulnerabilities affect the following programs: RealPlayer 10, 10.5 and 11, RealPlayer Enterprise, Linux RealPlayer 10, and Mac RealPlayer 10 and 10.1. So if you have one of these software products installed on your machine, you should patch and stay safe.

The discovery of the security threats is credited to Peter Vreugdenhil, Elazar Broad, Dyon Balding from Secunia, Haifei Li, as well as CERT/CC.

The first security vulnerability has been identified as CVE-2008-1309 and refers to the fact that "RealAudioObjects.RealAudio ActiveX control in rmoc3260.dll 6.0.10.45 in RealNetworks RealPlayer 11.0.1 build 6.0.14.794 does not properly manage memory for the Console property, which allows remote attackers to execute arbitrary code or cause a denial of service (browser crash) via a series of assignments of long string values, which triggers an overwrite of freed heap memory."

The second security threat has been identified as CVE-2008-3064 and according to RealNetworks it is a "local resource reference vulnerability". Further information about this security issue has not been yet disclosed.

The CVE-2007-5400 vulnerability, the third one to be discovered, allows an attacker to exploit a heap-based buffer overflow which can lead to arbitrary code execution. The overflow occurs because of the manner in which RealPlayer handles SWF (Shockwave Flash) files.

Last but not least, the CVE-2008-3066 vulnerability refers to the import method buffer overflow within RealPlayer Active X. According to Secunia, "a boundary error in rjbdll.dll can be exploited to cause a stack-based buffer overflow by importing a media library file using an ActiveX control and deleting the imported file."