Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

2021-10 Security Bulletin: Junos OS: MX Series: In subscriber management / BBE configuration authd can crash if a subscriber with a specific username tries to login leading to a DoS (CVE-2021-31366)

0

0

Article ID: JSA11228 SECURITY_ADVISORIES Last Updated: 13 Oct 2021Version: 3.0
Product Affected:
This issue affects all versions of Junos OS from 15.1 onwards. Affected platforms: MX Series
Problem:

An Unchecked Return Value vulnerability in the authd (authentication daemon) of Juniper Networks Junos OS on MX Series configured for subscriber management / BBE allows an adjacent attacker to cause a crash by sending a specific username. This impacts authentication, authorization, and accounting (AAA) services on the MX devices and leads to a Denial of Service (DoS) condition.

Continued receipted of these PPP login request will create a sustained Denial of Service (DoS) condition.

This issue affects Juniper Networks Junos OS on MX Series:

  • 15.1 versions prior to 15.1R7-S9;
  • 17.3 versions prior to 17.3R3-S12;
  • 17.4 versions prior to 17.4R3-S5;
  • 18.1 versions prior to 18.1R3-S13;
  • 18.2 versions prior to 18.2R3-S8;
  • 18.3 versions prior to 18.3R3-S5;
  • 18.4 versions prior to 18.4R3-S9;
  • 19.1 versions prior to 19.1R3-S6;
  • 19.2 versions prior to 19.2R1-S7, 19.2R3-S3;
  • 19.3 versions prior to 19.3R2-S6, 19.3R3-S3;
  • 19.4 versions prior to 19.4R3-S3;
  • 20.1 versions prior to 20.1R3;
  • 20.2 versions prior to 20.2R3-S1;
  • 20.3 versions prior to 20.3R3;
  • 20.4 versions prior to 20.4R3;
  • 21.1 versions prior to 21.1R2.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2021-31366.

Solution:

The following software releases have been updated to resolve this specific issue: 15.1R7-S9, 17.3R3-S12, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R3-S9, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R3-S3, 20.1R3, 20.2R3-S1, 20.3R3, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases.

This issue is being tracked as 1576182.

Workaround:

Please always configure a domain map none:

[access domain map none]
Implementation:
Software releases or updates are available for download at https://support.juniper.net/support/downloads/
Modification History:
2021-10-13: Initial Publication.
CVSS Score:
6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Severity Level:
Medium
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Related Links

Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search