Unpatched Zero-Days in Microsoft Edge and IE Browsers Disclosed Publicly

A security researcher today publicly disclosed details and
proof-of-concept exploits for two ‘unpatched’ zero-day
vulnerabilities in Microsoft’s web browsers after the company
allegedly failed to respond to his responsible private disclosure.

Both unpatched vulnerabilities—one of which affects the latest
version of Microsoft Internet Explorer and another affects
the latest Edge Browser—allow a remote attacker to bypass
same-origin policy on victim’s web browser.

Same Origin Policy (SOP) is a security feature
implemented in modern browsers that restricts a web-page or a
script loaded from one origin to interact with a resource from
another origin, preventing unrelated sites from interfering with
each other.

In other words, if you visit a website on your web browser, it can
only request data from the same origin [domain] the site was loaded
from, preventing it from making any unauthorized request on your
behalf in order to steal your data, from other sites.

However, the vulnerabilities discovered by security researcher
James Lee, who shared the details with The Hacker News,
could allow a malicious website to perform universal cross-site
scripting (UXSS) attacks against any domain visited using the
vulnerable Microsoft’s web browsers.

To successfully exploit these vulnerabilities, all attackers
need to do is convince a victim into opening the malicious website
[created by hacker], eventually allowing them to steal victim’s
sensitive data, like login session and cookies, from other sites
visited on the same browser.

The researcher contacted Microsoft and responsibly shared his
finding with the company ten months ago, that’s almost a year, but
the tech giant ignored the issues and did not respond to the
disclosure till the date, leaving both the flaws unpatched.
Lee has now released
proof-of-concept (PoCs) exploits for both issues.

The Hacker News has independently tested and confirmed both the
zero-day vulnerabilities against the latest version of Internet
Explorer and Edge running on a fully-patched Windows 10 operating
system.

The newly-disclosed vulnerabilities are similar to the ones
Microsoft patched last year in its Internet Explorer
(CVE-2018-8351) and Edge browsers (CVE-2018-8545).

Since the details and PoC for both the zero-days have already
been made publicly available, hackers won’t take much time to
exploit the flaws in an attempt to target Microsoft users.

What’s disappointing is that there is currently not much that
users can do to avoid this problem until Microsoft patches the
security issues. You can use other web browsers that are not
affected by this vulnerability, such as Chrome or Firefox.

^[1]