Microsoft Patches Windows Flaws Exploited in Attacks

Microsoft released patches for more than 90 vulnerabilities on Tuesday, including two critical remote code execution flaws that have been exploited in attacks and several weaknesses whose details have already been disclosed.

One of the actively exploited vulnerabilities is CVE-2017-8464, a LNK remote code execution flaw in Windows that is triggered when the icon of a specially crafted shortcut file is displayed.

“The attacker could present to the user a removable drive that contains a malicious shortcut file and an associated malicious binary. When the user opens this drive in Windows Explorer, or any other application that parses the icon of the shortcut, the malicious binary will execute code of the attacker’s choice on the target system,” Microsoft said in an advisory.

Researchers at the Zero Day Initiative (ZDI) pointed out that this vulnerability is similar to one exploited by the notorious Stuxnet worm, although they pointed out that CVE-2017-8464 may affect different parts of the code. In addition to the removable drive scenario described by Microsoft, ZDI said an attacker could also plant the malicious file in a remote location that is accessible to the targeted user.

Microsoft noted that the impact of this flaw is less severe if the targeted user does not have administrator rights.

Another vulnerability that has been actively exploited is CVE-2017-8543, a remote code execution bug affecting Windows Search.

“To exploit the vulnerability, the attacker could send specially crafted SMB messages to the Windows Search service. An attacker with access to a target computer could exploit this vulnerability to elevate privileges and take control of the computer,” Microsoft warned. “Additionally, in an enterprise scenario, a remote unauthenticated attacker could remotely trigger the vulnerability through an SMB connection and then take control of a target computer.”

Three of the vulnerabilities patched today by Microsoft – all of them affecting the Edge web browser – have already been publicly disclosed. They have been described as security feature bypass and information disclosure issues, but none of them has been rated critical.

A total of 18 flaws have been rated critical, while the rest are considered important. ZDI pointed out that the latest updates also patch vulnerabilities disclosed at Pwn2Own, but some bugs reported at the hacking competition still haven’t been addressed.

Adobe has also released updates on Tuesday to patch 20 vulnerabilities in Flash Player, Shockwave Player, Captivate and Digital Editions. Microsoft has included the Flash Player patches in its security updates.