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CVE-2021-31357

HIGHCVSS 7.8/10EPSS 0.63%

Last modified

CVE-2021-31357 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. A command injection vulnerability in tcpdump 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. EPSS estimates a 0.63% chance of exploitation in the next 30 days.

Description

A command injection vulnerability in tcpdump 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 20.3R2-S1-EVO; 20.4 versions prior to 20.4R2-S2-EVO; 21.1 versions prior to 21.1R2-EVO; 21.2 versions prior to 21.2R1-S1-EVO, 21.2R2-EVO.

Metrics

CVSS 3.1
7.8/10

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

EPSS Probability
0.63%

45.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
JuniperJunos Os Evolved<= 20.3—
JuniperJunos Os Evolved20.4R1
JuniperJunos Os Evolved21.1—
JuniperJunos Os Evolved21.2R1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-31357?
A command injection vulnerability in tcpdump 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 20.3R2-S1-EVO; 20.4 versions prior to 20.4R2-S2-EVO; 21.1 versions prior to 21.1R2-EVO; 21.2 versions prior to 21.2R1-S1-EVO, 21.2R2-EVO.
How severe is CVE-2021-31357?
CVE-2021-31357 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.63% probability of exploitation in the next 30 days.
How do I fix CVE-2021-31357?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31357?

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Source: NVD / NIST