CVE-2021-31354 - CVE House
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Status published High 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)

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Juniper SIRT would like to acknowledge and thank The UK's National Cyber Security Centre (NCSC) for responsibly reporting this vulnerability.

Affected Vendor

Juniper Networks

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Affected Software

Junos OS, Junos OS Evolved
Vulnerable Versions:
unspecified, 19.2, 19.3, 20.1, 20.2, 20.3, 20.4, 21.1, 20.1R1-EVO

Timeline

Official Publish: October 19th, 2021
Last Modified: September 17th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L

Weaknesses (CWE)