GNOME gnome-shell up to 3.9.1 Screen Lock access control

Summaryinfo

A vulnerability has been found in GNOME gnome-shell up to 3.9.1 and classified as problematic. The impacted element is an unknown function of the component Screen Lock. The manipulation leads to access control. This vulnerability is uniquely identified as CVE-2013-7221. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in GNOME gnome-shell up to 3.9.1. This issue affects an unknown part of the component Screen Lock. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The automatic screen lock functionality in GNOME Shell (aka gnome-shell) before 3.10 does not prevent access to the "Enter a Command" dialog, which allows physically proximate attackers to execute arbitrary commands by leveraging an unattended workstation.

The weakness was disclosed 04/29/2014 as confirmed git commit (GIT Repository). It is possible to read the advisory at git.gnome.org. The identification of this vulnerability is CVE-2013-7221 since 12/26/2013. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The following code is the reason for this vulnerability:

if (!sessionMode.hasRunDialog && lookingGlass)
   lookingGlass.close();

Upgrading to version 3.9.2 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.gnome.org. The best possible mitigation is suggested to be patching the affected component. The vulnerability will be addressed with the following lines of code:

if (!sessionMode.hasRunDialog) {
   if (runDialog)
      runDialog.close();
   if (lookingGlass)
      lookingGlass.close();
}

The entry VDB-69526 is pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• GNOME

Name

• gnome-shell

Version

• 3.9.0
• 3.9.1

License

• open-source

Website

• Vendor: https://www.gnome.org/

CPE 2.3info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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