CVE-2021-31354

Junos OS and Junos OS Evolved: A vulnerability in the Juniper Agile License Client may allow an attacker to perform Remote Code Execution (RCE)

Description

An Out Of Bounds (OOB) access vulnerability in the handling of responses by a Juniper Agile License (JAL) Client in Juniper Networks Junos OS and Junos OS Evolved, configured in Network Mode (to use Juniper Agile License Manager) may allow an attacker to cause a partial Denial of Service (DoS), or lead to remote code execution (RCE). The vulnerability exists in the packet parsing logic on the client that processes the response from the server using a custom protocol. An attacker with control of a JAL License Manager, or with access to the local broadcast domain, may be able to spoof a new JAL License Manager and/or craft a response to the Junos OS License Client, leading to exploitation of this vulnerability. This issue only affects Junos systems configured in Network Mode. Systems that are configured in Standalone Mode (the default mode of operation for all systems) are not vulnerable to this issue. This issue affects: Juniper Networks Junos OS: 19.2 versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS Evolved: version 20.1R1-EVO and later versions, prior to 21.2R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R1.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS 19.3R3-S3, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases. Junos OS Evolved 21.2R2-EVO, 21.3R1-EVO, and all subsequent releases.

Workaround:

  • Disable Network Mode and configure the Junos License Client to use Standalone Mode: user@junos# set system license standalone-mode

Category

7.1
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.28%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11219 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-31354?
CVE-2021-31354 has been scored as a high severity vulnerability.
How to fix CVE-2021-31354?
To fix CVE-2021-31354: The following software releases have been updated to resolve this specific issue: Junos OS 19.3R3-S3, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases. Junos OS Evolved 21.2R2-EVO, 21.3R1-EVO, and all subsequent releases.
Is CVE-2021-31354 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-31354 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-31354?
CVE-2021-31354 affects Juniper Networks Junos OS, Juniper Networks Junos OS Evolved.
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