Microsoft released five security bulletins on Tuesday as part of its monthly update cycle, warning of vulnerabilities that put computers running Windows at risk of attack.
The flaws affect desktop as well as server installations of multiple Windows versions. However, none are rated "critical," Microsoft's highest severity rating.
They are all listed as "important", which means they require a user action to spread a worm, but could still expose user data or threaten system resources.
A set of vulnerabilities in the Windows word processing application WordPad affects many Windows releases, including Windows XP Service Pack 2 (SP2) and Windows Server 2003.
An attacker could exploit the flaws to gain complete control of the systems, Microsoft warned. The WordPad flaws lie in conversion components of the application.
To exploit the vulnerabilities, an attacker would have to lure a victim to a specially crafted web page or send an attachment in an e-mail.
Microsoft deems the WordPad issue "important" on systems running Windows NT 4.0, Windows 2000 and Windows XP with Service Pack 1. Those running Windows XP SP2 or Windows Server 2003 are at lesser risk and an installation of Microsoft Word mitigates the risk.
A security vulnerability in HyperTerminal affects the same Windows releases. A buffer overrun flaw in the Windows communications application could allow an attacker to take over a victim's system if the victim opened a malicious HyperTerminal file.
The HyperTerminal issue is "important" for systems running Windows NT 4.0, Windows 2000 and Windows XP. HyperTerminal is not installed by default on Windows Server 2003. Microsoft rates the issue "moderate" for that operating system.
Two flaws in the operating system's DHCP server service are Limited to Windows NT Server 4.0. One could allow an attacker to launch a denial of service attack, disabling the DHCP service. The other could allow remote code execution.
Flaws in the Windows Internet Name Service (WINS) affect Windows NT Server 4.0, Windows 2000 Server and Windows Server 2003. An attacker could gain control of a system running the software by constructing a malicious network packet.
WINS is a network infrastructure component. It provides a distributed database for registering and querying dynamic computer name-to-IP address mapping in a routed network. Details of a WINS flaw were first published last month on the BugTraq mailing list by security company Immunity.
Finally, Microsoft warned of security flaws in the Windows kernel and the Windows Local Security Authority Subsystem Service (LSASS). Both are privilege escalation vulnerabilities, which could allow an attacker who has already logged on to a system to escalate his privileges and get full access, Microsoft said.
The kernel and LSASS issues affect Windows NT Server 4.0, Windows 2000, Windows XP and Windows Server 2003, Microsoft said in bulletin MS04-044.
The next "patch Tuesday" will the second Tuesday of January.
Joris Evers writes for IDG News Service