CVE Vulnerabilities

CVE-2018-0422

Incorrect Permission Assignment for Critical Resource

Published: Oct 05, 2018 | Modified: Oct 03, 2019
CVSS 3.x
7.3
HIGH
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.9 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the folder permissions of Cisco Webex Meetings client for Windows could allow an authenticated, local attacker to modify locally stored files and execute code on a targeted device with the privilege level of the user. The vulnerability is due to folder permissions that grant a user the permission to read, write, and execute files in the Webex folders. An attacker could exploit this vulnerability to write malicious files to the Webex client directory, affecting all other users of the targeted device. A successful exploit could allow a user to execute commands with elevated privileges. Attacks on single-user systems are less likely to occur, as the attack must be carried out by the user on the users own system. Multiuser systems have a higher risk of exploitation because folder permissions have an impact on all users of the device. For an attacker to exploit this vulnerability successfully, a second user must execute the locally installed malicious file to allow remote code execution to occur.

Weakness

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Affected Software

Name Vendor Start Version End Version
Webex_meetings_online Cisco * *
Webex_meetings_online Cisco t31.20 t31.20
Webex_meetings_online Cisco t31.20.2 t31.20.2

Potential Mitigations

  • Run the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
  • OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
  • This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
  • Be careful to avoid CWE-243 and other weaknesses related to jails.

References