What is the CVSS score of CVE-2021-31356?

CVE-2021-31356 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.9%.

Junos Os Evolved CVE-2021-31356

HIGH

Command Injection (CWE-77)

2021-10-19 sirt@juniper.net

Command Injection Juniper Junos Os Evolved

7.8

CVSS 3.1 · Vendor: juniper

Severity by source

Vendor (juniper) PRIMARY

7.8 HIGH

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from Vendor (juniper) · only source for this CVE.

CVSS VectorVendor: juniper

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Oct 19, 2021 - 19:15 cve.org

HIGH 7.8

DescriptionCVE.org

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.

AnalysisAI

Technical ContextAI

This vulnerability is classified as Command Injection (CWE-77), which allows attackers to inject arbitrary commands into system command execution. 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.4R3-S1-EVO; All versions of 21.1-EVO and 21.2-EVO. Affected products include: Juniper Junos Os Evolved. Version information: prior to 20.4.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use parameterized APIs, avoid shell execution, validate input with strict allowlists.