As the dust settles on the notorious IE zero-day exploit which was fixed in October’s Patch Tuesday, a fresh zero-day utilizing Tagged Image File Format (TIFF) files makes an appearance.

Amidst the many Microsoft vulnerabilities which appear every month, it would seem to be a growing trend that one or two will, figuratively speaking, rise to prominence above the others. Chiefly, this has been the TIFF exploit which is currently affecting various Microsoft products such as Office 2003 – 2007, Windows Vista, Windows Server 2003 and Microsoft Lync.

Although the vulnerability doesn’t affect the latest versions of Microsoft software – think Windows 8, Office 2013, Windows Server 2008 – that will hardly be comforting to those who still use the preceding versions.

Nevertheless, there is a bit of user interaction required for the vulnerability to be successfully exploited. A system cannot be compromised without the user opening or previewing specially crafted content, such as an engineered web page or email attachment. If a user is lured into accessing this content, a flaw in the handling of TIFF image files by the graphics processing components of the affected software will allow an attacker to execute code with the same privileges as the logged-in user. This of course could be particularly damaging if the user were to have administrator privileges, as opposed to a standard user account.

So far, Microsoft is only aware of attacks on Office 2007, mainly in the Middle East and South Asia regions where Windows XP was the operating system. In these targeted attacks, users were asked to open a Word attachment with the malformed image embedded inside.

No patch available as yet

Unfortunately, Microsoft have stated that they will not be releasing a patch for this vulnerability in today’s round of Patch Tuesday fixes, which includes 8 Bulletins. However, Microsoft are actively working on a resolution which will be released when ready, indicating that there may be an out-of-cycle update on the horizon.

In the meantime, whilst not intended as a replacement for the upcoming update, Microsoft has provided a temporary ‘Fix It’ solution via Security Advisory 2896666 which is recommended to help protect systems.

Bearing in mind that there will not be a fix provided today, users are encouraged to exercise caution when invited to unknown websites and receiving unexpected email attachments.