Effects
MS09-058 is not categorized as virus, worm, Trojan or backdoor. It is a group of important vulnerabilities in the Windows Kernel on Windows Server 2008/7/Vista/2003/XP/2000 computers, which allows to gain local privilege escalation.
The kernel is the core of the operating system and provides basic services for all other parts of the operating system.
The addressed vulnerabilities are:
- Windows Kernel Exception Handler vulnerability: it occurs because the Windows kernel does not properly handle certain exceptions.
- Windows Kernel Double Free vulnerability: it occurs because the Windows kernel does not correctly reset a pointer when freeing memory.
If exploited successfully, MS09-058 allows to gain unauthorized privileges on a computer or network. An example of privilege elevation would be an unprivileged user who could manage to be added to the Administrator's group. In such case, the hacker could take complete control of the system: create, modify or delete files, install programs, create new user accounts, etc.
MS09-058 is usually exploited by running a specially crafted program in the vulnerable computer. In order to do so, a hacker must be able to log on locally to the system.
If you have a Windows Server 2008/7/Vista/2003/XP/2000 computer, it is recommended to download and apply the security patch for this vulnerability. Click here to access the web page for downloading the patch.
Bear in mind that this security patch replaces a previous one, called MS09-058.