7.8
HIGH
CVE-2021-31356
Juniper Networks Junos OS Evolved Bypass CLI Command Restrictions Command Injection
Description

A command injection vulnerability in command processing on Juniper Networks Junos OS Evolved allows an attacker with authenticated CLI access to be able to bypass configured access protections to execute arbitrary shell commands within the context of the current user. The vulnerability allows an attacker to bypass command authorization restrictions assigned to their specific user account and execute commands that are available to the privilege level for which the user is assigned. For example, a user that is in the super-user login class, but restricted to executing specific CLI commands could exploit the vulnerability to execute any other command available to an unrestricted admin user. This vulnerability does not increase the privilege level of the user, but rather bypasses any CLI command restrictions by allowing full access to the shell. This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S1-EVO; All versions of 21.1-EVO and 21.2-EVO.

INFO

Published Date :

Oct. 19, 2021, 7:15 p.m.

Last Modified :

Oct. 25, 2022, 3:33 p.m.

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2021-31356 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Juniper junos_os_evolved
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-31356.

URL Resource
https://kb.juniper.net/JSA11221 Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-31356 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-31356 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Reanalysis by [email protected]

    Oct. 25, 2022

    Action Type Old Value New Value
    Removed CWE NIST CWE-77
    Added CWE NIST CWE-78
  • Initial Analysis by [email protected]

    Oct. 26, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:C/I:C/A:C)
    Changed Reference Type https://kb.juniper.net/JSA11221 No Types Assigned https://kb.juniper.net/JSA11221 Vendor Advisory
    Added CWE NIST CWE-77
    Added CPE Configuration OR *cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* versions up to (including) 20.3 *cpe:2.3:o:juniper:junos_os_evolved:20.4:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:20.4:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.1:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.1:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.1:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.1:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos_os_evolved:21.2:r2:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-31356 is associated with the following CWEs:

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.04 }} 0.00%

score

0.10781

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability