CVE Vulnerabilities

CVE-2021-34724

Improper Access Control

Published: Sep 23, 2021 | Modified: Nov 21, 2024
CVSS 3.x
6
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
CVSS 2.x
6.6 MEDIUM
AV:L/AC:L/Au:N/C:C/I:C/A:N
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to elevate privileges and execute arbitrary code on the underlying operating system as the root user. An attacker must be authenticated on an affected device as a PRIV15 user. This vulnerability is due to insufficient file system protection and the presence of a sensitive file in the bootflash directory on an affected device. An attacker could exploit this vulnerability by overwriting an installer file stored in the bootflash directory with arbitrary commands that can be executed with root-level privileges. A successful exploit could allow the attacker to read and write changes to the configuration database on the affected device.

Weakness

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected Software

Name Vendor Start Version End Version
Ios_xe_sd-wan Cisco * 17.3.1a (including)

Extended Description

Access control involves the use of several protection mechanisms such as:

When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses:

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References