CVE-2021-0226

Junos OS Evolved: The IPv6 BGP session will flap due to receipt of a specific IPv6 packet

Description

On Juniper Networks Junos OS Evolved devices, receipt of a specific IPv6 packet may cause an established IPv6 BGP session to terminate, creating a Denial of Service (DoS) condition. Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue does not affect IPv4 BGP sessions. This issue affects IBGP or EBGP peer sessions with IPv6. This issue affects: Juniper Networks Junos OS Evolved: 19.4 versions prior to 19.4R2-S3-EVO; 20.1 versions prior to 20.1R2-S3-EVO; 20.2 versions prior to 20.2R2-S1-EVO; 20.3 versions prior to 20.3R2-EVO. This issue does not affect Juniper Networks Junos OS releases.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 19.4R2-S3-EVO, 20.1R2-S3-EVO, 20.2R2-S1-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.

Workaround:

  • There are no viable workarounds for this issue.

Category

7.1
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.54%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11121 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-0226?
CVE-2021-0226 has been scored as a high severity vulnerability.
How to fix CVE-2021-0226?
To fix CVE-2021-0226: The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 19.4R2-S3-EVO, 20.1R2-S3-EVO, 20.2R2-S1-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.
Is CVE-2021-0226 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-0226 is being actively exploited. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-0226?
CVE-2021-0226 affects Juniper Networks Junos OS Evolved.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.