Support Support Downloads Knowledge Base Case Manager My Juniper 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

2021-01 Security Bulletin: Junos OS: MX Series: Dynamic filter fails to match IPv6 prefix (CVE-2021-0205)

0

0

Article ID: JSA11095 SECURITY_ADVISORIES Last Updated: 13 Jan 2021Version: 1.0
Product Affected:
This issue affects Junos OS 17.3, 17.4, 18.1, 18.2, 18.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1, 20.2. Affected platforms: MX Series.
Problem:

When the "Intrusion Detection Service" (IDS) feature is configured on Juniper Networks MX series with a dynamic firewall filter using IPv6 source or destination prefix, it may incorrectly match the prefix as /32, causing the filter to block unexpected traffic.

This issue affects only IPv6 prefixes when used as source and destination.

This issue affects MX Series devices using MS-MPC, MS-MIC or MS-SPC3 service cards with IDS service configured.

This issue affects Juniper Networks Junos OS:

  • 17.3 versions prior to 17.3R3-S10 on MX Series;
  • 17.4 versions prior to 17.4R3-S3 on MX Series;
  • 18.1 versions prior to 18.1R3-S11 on MX Series;
  • 18.2 versions prior to 18.2R3-S6 on MX Series;
  • 18.3 versions prior to 18.3R3-S4 on MX Series;
  • 18.4 versions prior to 18.4R3-S6 on MX Series;
  • 19.1 versions prior to 19.1R2-S2, 19.1R3-S3 on MX Series;
  • 19.2 versions prior to 19.2R3-S1 on MX Series;
  • 19.3 versions prior to 19.3R2-S5, 19.3R3-S1 on MX Series;
  • 19.4 versions prior to 19.4R3 on MX Series;
  • 20.1 versions prior to 20.1R2 on MX Series;
  • 20.2 versions prior to 20.2R2 on MX Series;

The example of the configuration stanza affected by this issue is as follows:

[services ids]

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-2021-0205.

Solution:

The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S10, 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R3-S4, 18.4R3-S6, 19.1R2-S2, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3-S1, 19.4R3, 20.1R2, 20.2R2, 20.3R1 and all subsequent releases.

This issue is being tracked as 1536100.

Workaround:

IDS configuration can be disabled.

Implementation:
Software releases or updates are available for download at https://www.juniper.net/support/downloads/.
Modification History:
2021-01-13: Initial Publication.
CVSS Score:
5.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L)
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