Microsoft warns IE flaw is being exploited
A flaw affecting all versions of IE is being exploited in the wild, Microsoft warns.


Microsoft has warned a vulnerability in Internet Explorer (IE) has been exploited in the wild.
The Redmond firm has updated the advisory for the flaw, which reared its head just before Christmas and derives from the way IE handles cascading style sheets (CSS).
The CSS vulnerability affects all versions of IE and could allow a hacker to initiate remote code execution.
"This vulnerability requires an attacker to provide a CSS style sheet that includes a reference to itself with an @import command," explained Kevin Brown, a member of the Microsoft Security Response Centre engineering team, in a blog post.
"When Internet Explorer tries to load this recursive style sheet, it corrupts memory in a way that could be exploited for arbitrary code execution."
Microsoft has included a workaround in its advisory to help users protect systems whilst the tech giant works on an update.
For the workaround to function correctly, Microsoft said users would need to have implemented the latest security updates, including MS10-090, which was released on 14 December 2010.
Sign up today and you will receive a free copy of our Future Focus 2025 report - the leading guidance on AI, cybersecurity and other IT challenges as per 700+ senior executives
"This workaround is an MSI package (Microsoft "FixIt") that uses the Windows application compatibility toolkit to make a small change to MSHTML.DLL every time it is loaded by Internet Explorer," Brown explained.
"This change causes Internet Explorer to refuse to import a CSS style sheet if it has the same URL as the CSS style sheet from which it is being loaded. Simply put, the workaround inserts a check to see if a style sheet is about to be loaded recursively, and if it [is] so, it aborts the load of the style sheet."
The workaround was issued on the same day as the first Patch Tuesday of 2010, in which another zero-day vulnerability affecting the Windows Graphics Rendering Engine was left unfixed.
Tom Brewster is currently an associate editor at Forbes and an award-winning journalist who covers cyber security, surveillance, and privacy. Starting his career at ITPro as a staff writer and working up to a senior staff writer role, Tom has been covering the tech industry for more than ten years and is considered one of the leading journalists in his specialism.
He is a proud alum of the University of Sheffield where he secured an undergraduate degree in English Literature before undertaking a certification from General Assembly in web development.
-
Is the traditional MSP service desk dead?
Industry Insights AI and B2C expectations are reshaping B2B service desks and MSP strategy
-
From phone calls to roll calls: 3CX has the answer
How Yellowgrid, a 3CX Platinum distributor, has taken advantage of 3CX Phone System’s customisable nature to create a time-saving solution already embraced by over 100 UK schools
-
Flaw in Lenovo’s customer service AI chatbot could let hackers run malicious code, breach networks
News Hackers abusing the Lenovo flaw could inject malicious code with just a single prompt
-
Industry welcomes the NCSC’s new Vulnerability Research Initiative – but does it go far enough?
News The cybersecurity agency will work with external researchers to uncover potential security holes in hardware and software
-
Hackers are targeting Ivanti VPN users again – here’s what you need to know
News Ivanti has re-patched a security flaw in its Connect Secure VPN appliances that's been exploited by a China-linked espionage group since at least the middle of March.
-
Broadcom issues urgent alert over three VMware zero-days
News The firm says it has information to suggest all three are being exploited in the wild
-
Nakivo backup flaw still present on some systems months after firms’ ‘silent patch’, researchers claim
News Over 200 vulnerable Nakivo backup instances have been identified months after the firm silently patched a security flaw.
-
Everything you need to know about the Microsoft Power Pages vulnerability
News A severe Microsoft Power Pages vulnerability has been fixed after cyber criminals were found to have been exploiting unpatched systems in the wild.
-
Vulnerability management complexity is leaving enterprises at serious risk
News Fragmented data and siloed processes mean remediation is taking too long
-
A critical Ivanti flaw is being exploited in the wild – here’s what you need to know
News Cyber criminals are actively exploiting a critical RCE flaw affecting Ivanti Connect Secure appliances