CVE-2021-0239

Junos OS Evolved: Denial of Service due to receipt of specific genuine layer 2 frames.

Description

In Juniper Networks Junos OS Evolved, receipt of a stream of specific genuine Layer 2 frames may cause the Advanced Forwarding Toolkit (AFT) manager process (Evo-aftmand), responsible for handling Route, Class-of-Service (CoS), Firewall operations within the packet forwarding engine (PFE) to crash and restart, leading to a Denial of Service (DoS) condition. By continuously sending this specific stream of genuine Layer 2 frames, an attacker can repeatedly crash the PFE, causing a sustained Denial of Service (DoS). This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R1-EVO. This issue does not affect Junos OS versions.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 20.4R1-EVO, and all subsequent releases.

Workaround:

  • There are no viable workarounds for this issue.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.20%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11134 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-0239?
CVE-2021-0239 has been scored as a medium severity vulnerability.
How to fix CVE-2021-0239?
To fix CVE-2021-0239: The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 20.4R1-EVO, and all subsequent releases.
Is CVE-2021-0239 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-0239 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-0239?
CVE-2021-0239 affects Juniper Networks Junos OS Evolved.
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