CVE-2018-0021 Explained : Impact and Mitigation

Juniper Networks Junos OS is susceptible to a vulnerability where short MacSec keys could lead to man-in-the-middle attacks. Attackers may exploit this weakness to discover secret passphrases through various attacks.

Understanding CVE-2018-0021

This CVE involves the risk of attackers discovering secret passphrases due to short MacSec keys in Juniper Networks Junos OS.

What is CVE-2018-0021?

If the connectivity association name (CKN) or connectivity association key (CAK) has insufficient digits, Juniper devices are at risk of attackers uncovering secret passphrases through dictionary and brute-force attacks.

The Impact of CVE-2018-0021

CVSS Base Score: 8.8 (High)
Attack Vector: Adjacent Network
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: High
Privileges Required: None
Scope: Changed
User Interaction: Required
Attack Complexity: Low

Technical Details of CVE-2018-0021

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability arises from the auto-configuration of remaining digits to 0 if CKN or CAK keys are insufficient, making secret passphrases vulnerable to discovery.

Affected Systems and Versions

Junos OS versions prior to 14.1R10, 14.1R9
14.1X53 versions prior to 14.1X53-D47
15.1 versions prior to 15.1R4-S9, 15.1R6-S6, 15.1R7
15.1X49 versions prior to 15.1X49-D100
15.1X53 versions prior to 15.1X53-D59
16.1 versions prior to 16.1R3-S8, 16.1R4-S8, 16.1R5
16.2 versions prior to 16.2R1-S6, 16.2R2
17.1 versions prior to 17.1R2

Exploitation Mechanism

Juniper SIRT has not detected any malicious exploitation of this vulnerability.

Mitigation and Prevention

Learn how to mitigate and prevent the CVE-2018-0021 vulnerability.

Immediate Steps to Take

Configure all 64 digits of a CKN
Configure all 32 digits of a CAK
Refer to Junos task topic 'macsec' for further guidance

Long-Term Security Practices

Regularly update Junos OS to the latest patched versions
Implement strong encryption practices
Monitor network traffic for any suspicious activities

Patching and Updates

Update to the following software releases: 14.1R9, 14.1X53-D47, 15.1R4-S9, 15.1R6-S6, 15.1R7, 15.1X49-D100, 15.1X53-D59, 16.1R3-S8, 16.1R4-S8, 16.1R5, 16.2R1-S6, 16.2R2, 17.1R2, 17.2R1, and all subsequent releases.