Critical Code Injection Flaw Inwards Gnome File Managing Director Leaves Linux Users Opened Upwards To Hacking

Influenza A virus subtype H5N1 safety researcher has discovered a code injection vulnerability inwards the thumbnail handler element of GNOME Files file manager that could allow hackers to execute malicious code on targeted Linux machines.

Dubbed Bad Taste, the vulnerability (CVE-2017-11421) was discovered yesteryear German linguistic communication researcher Nils Dagsson Moskopp, who also released proof-of-concept code on his weblog to demonstrate the vulnerability.

The code injection vulnerability resides in "gnome-exe-thumbnailer" — a tool to generate thumbnails from Windows executable files (.exe/.msi/.dll/.lnk) for GNOME, which requires users to stimulate got Wine application installed on their systems to opened upwards it.

Those who are unaware, Wine is a complimentary too open-source software that allows Windows applications to run on the Linux operating system.

Moskopp discovered that spell navigating to a directory containing the .msi file, GNOME Files takes the filename every bit an executable input too run it inwards social club to create an icon thumbnail.

For successful exploitation of the vulnerability, an aggressor tin shipping a crafted Windows installer (MSI) file amongst malicious VBScript code inwards its filename, which if downloaded on a vulnerable organisation would compromise the machine without farther user interaction.

"Instead of parsing an MSI file to larn its version number, this code creates a script containing the filename for which a thumbnail should survive shown too executes that using Wine," Moskopp explains spell demonstrating his PoC. 

"The script is constructed using a template, which makes it possible to embed VBScript inwards a filename too trigger its execution."

The flaw tin survive exploited yesteryear potential hackers using other ready on vectors every bit well, for example, yesteryear straight inserting a USB-drive amongst a malicious file stored on it, or delivering the malicious file via drive-by-downloads.

How to Protect Yourself from Bad Taste

Moskopp reported the vulnerability to the GNOME Project too the Debian Project. Both of them patched the vulnerability inwards the gnome-exe-thumbnailer file.

The vulnerability affects gnome-exe-thumbnailer earlier 0.9.5 version. So, if y'all run a Linux OS amongst the GNOME desktop, depository fiscal establishment tally for updates straightaway earlier y'all larn affected yesteryear this critical vulnerability.

Meanwhile, Moskopp also advised users to:

• Delete all files inwards /usr/share/thumbnailers.
• Do non role GNOME Files.
• Uninstall whatever software that facilitates automatically execution of filenames every bit code.

Moskopp also advised developers to non role "bug-ridden ad-hoc parsers" to parse files, to "fully recognise inputs earlier processing them," too to role unparsers, instead of templates.

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