#VU39101 Input validation error in gnome-shell - CVE-2017-8288

Vulnerability identifier: #VU39101

Vulnerability risk: High

CVSSv4.0: 7.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-8288

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
gnome-shell
Client/Desktop applications / Software for system administration

Vendor: Gnome Development Team

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

gnome-shell 3.22 through 3.24.1 mishandles extensions that fail to reload, which can lead to leaving extensions enabled in the lock screen. With these extensions, a bystander could launch applications (but not interact with them), see information from the extensions (e.g., what applications you have opened or what music you were playing), or even execute arbitrary commands. It all depends on what extensions a user has enabled. The problem is caused by lack of exception handling in js/ui/extensionSystem.js.

Mitigation
Install update from vendor's website.

Vulnerable software versions

gnome-shell: 3.22.0 - 3.24.1

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External links
https://www.securityfocus.com/bid/98070
https://bugs.kali.org/view.php?id=2513
https://bugzilla.gnome.org/show_bug.cgi?id=781728
https://github.com/EasyScreenCast/EasyScreenCast/issues/46
https://github.com/GNOME/gnome-shell/commit/ff425d1db7082e2755d2a405af53861552acf2a1

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.