Patch Tuesday Serious security flaws in Outlook and Edge are headlining a busy Microsoft Patch Tuesday.
The Redmond giant has issued the February edition of its monthly security update, addressing a total of 50 CVE-listed vulnerabilities in its products. Adobe has also posted an update for flaws in Reader and Experience Manager.
Microsoft, my bloody (insecure) valentine
Headlining the Microsoft patch load is a fix for an Outlook bug, CVE-2018-0852, which is a memory corruption flaw that can be exploited to achieve remote code execution.
Opening a maliciously crafted message attachment or viewing it in the Outlook Preview window pane is enough to trigger the bug and allow nasty code within the file to start running. This code can start installing malware or attempt to hijack the whole machine, and so on.
Microsoft explained in its advisory:
Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Outlook software. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file.
Infosec bods noted that, though the flaw is not right now being exploited in the wild, patching it should be a top priority for admins.
"This bug allows an attacker to get code execution through vulnerable versions of Microsoft Outlook," wrote Dustin Childs of Zero Day Initiative.
"What’s truly frightening with this bug is that the Preview Pane is an attack vector, which means simply viewing an email in the Preview Pane could allow code execution."
Another Outlook programming cockup fixed this month, CVE-2018-0850, is a bonkers elevation-of-privilege bug triggered when the email client receives a specially crafted message that forces it to load a message store over SMB from a local or remote server. Because the flaw can be exploited when the message is merely received, before it is even opened, the attack could take place without any user interaction.
"To exploit the vulnerability, the attacker could send a specially crafted email to a victim," Microsoft explained. "Outlook would then attempt to open a pre-configured message store contained in the email upon receipt of the email. This update addresses the vulnerability by ensuring Office fully validates incoming email formatting before processing message content."
Best patch that security blunder as soon as possible, too. Both bugs were found and reported by Nicolas Joly of Pwn2Own fame.
As per usual, the Edge and Internet Explorer browsers each collected a number of bug fixes, both for exploitable flaws in the browsers themselves and in their scripting engines. In all 11 different CVE-listed memory corruption vulnerabilities, allowing for full remote code execution by malicious webpages, were disclosed and patched.
Visiting a booby-trapped website is enough to exploit these holes, and allow malware to run on your Windows system, so get patching as soon as possible, please.
Edge was also the subject of the lone publicly-disclosed flaw for this month. CVE-2018-0771 is a bypass for the browser's Same-Origin Policy (SOP) settings. An attacker could craft a webpage to bypass the SOP restrictions and get the browser to send data like cookies from other sites.
"While interesting from a technical viewpoint," said Childs, "this is not as likely to see much use outside of very targeted attacks in the wild."
Other problems in Edge include a pair of information disclosure flaws (CVE-2018-0763 and CVE-2018-0839), while Internet Explorer got a patch to address CVE-2018-0847, a bug that would let a webpage use VBScript to pull stored information from memory.
CVE-2018-0825 is a remote code execution flaw in the StructuredQuery component for Windows and Windows Server that can be exploited via either a malicious web page or an email attachment.
Windows Kernel was on the receiving end of patches for 10 different CVE listings, including five elevation of privilege flaws and five information disclosure vulnerabilities. Each of those could be exploited locally by a malicious application to gain sufficient powers to commandeer the whole machine.
Office, meanwhile, was on the receiving end of fixes for CVE-2018-0841, a remote code execution hole exploited through dodgy Excel spreadsheets, CVE-2018-0851, a remote code flaw targeted by any kind of Office document, and CVE-2018-0853, an information flaw that lets Office documents read out of bound memory contents.
Skype 'flaw' flap
A DLL hijacking issue in Skype was discovered and reported by researcher Stefan Kanthak back in September, and disclosed this month. The vulnerability was fixed in October – so make sure you're running version 8 of Skype for Windows, and you're all set.
Massive patch for Reader and Acrobat
Adobe also has a major release for February. The Reader and Acrobat apps for both Windows and MacOS have been updated to address 39 CVE-listed flaws.
Of those, 24 address remote code execution from out of bounds read errors, seven cover arbitrary code execution via out of bounds write errors, five address use-after free arbitrary code execution bugs, five cover use-after-free bugs, and four cover heap overflow vulnerabilities. One other flaw, CVE-2018-4872, addresses a security bypass error that allows privilege escalation.
Opening booby-trapped documents is enough to exploit these flaws to execute malicious code on a vulnerable system.
Those running the Adobe Experience Manager content management system will also need to install an update that addresses a pair of cross-site scripting flaws, CVE-2018-4875 and CVE-2018-4876. ®