CVE-2021-31365

Junos OS: EX2300, EX3400 and EX4300 Series: An Aggregated Ethernet (AE) interface will go down due to a stream of specific layer 2 frames

Description

An Uncontrolled Resource Consumption vulnerability in Juniper Networks Junos OS on EX2300, EX3400 and EX4300 Series platforms allows an adjacent attacker sending a stream of layer 2 frames will trigger an Aggregated Ethernet (AE) interface to go down and thereby causing a Denial of Service (DoS). By continuously sending a stream of specific layer 2 frames an attacker will sustain the Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS EX4300 Series All versions prior to 15.1R7-S7; 16.1 versions prior to 16.1R7-S8; 17.1 versions prior to 17.1R2-S12; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S10, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S3; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S2, 19.3R3; 19.4 versions prior to 19.4R1-S2, 19.4R2. Juniper Networks Junos OS EX3400 and EX4300-MP Series All versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R2-S9, 18.4R3-S7; 19.1 versions prior to 19.1R2-S3, 19.1R3-S4; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R2. Juniper Networks Junos OS EX2300 Series All versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R2-S3, 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R2.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue in Junos OS - For EX4300 Series: 15.1R7-S7, 16.1R7-S8, 17.1R2-S12, 17.2R3-S4, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S3, 18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S1, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S2, 19.4R2, 20.1R1, and all subsequent releases. - For EX3400 and EX4300-MP Series: 18.1R3-S12, 18.2R3-S7, 18.3R3-S4, 18.4R2-S9, 18.4R3-S7, 19.1R2-S3, 19.1R3-S4, 19.2R3-S1, 19.3R3-S1, 19.4R3-S1, 20.1R3, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases. -For EX2300 Series: 18.3R3-S5, 18.4R2-S9, 18.4R3-S9, 19.1R2-S3, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S7, 19.3R3-S3, 19.4R3-S5, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 20.4R2-S1, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases.

Workaround:

  • Disabling LLDP configuration will prevent this issue.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.08%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11227 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-31365?
CVE-2021-31365 has been scored as a medium severity vulnerability.
How to fix CVE-2021-31365?
To fix CVE-2021-31365: The following software releases have been updated to resolve this specific issue in Junos OS - For EX4300 Series: 15.1R7-S7, 16.1R7-S8, 17.1R2-S12, 17.2R3-S4, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S3, 18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S1, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S2, 19.4R2, 20.1R1, and all subsequent releases. - For EX3400 and EX4300-MP Series: 18.1R3-S12, 18.2R3-S7, 18.3R3-S4, 18.4R2-S9, 18.4R3-S7, 19.1R2-S3, 19.1R3-S4, 19.2R3-S1, 19.3R3-S1, 19.4R3-S1, 20.1R3, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases. -For EX2300 Series: 18.3R3-S5, 18.4R2-S9, 18.4R3-S9, 19.1R2-S3, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S7, 19.3R3-S3, 19.4R3-S5, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 20.4R2-S1, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases.
Is CVE-2021-31365 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-31365 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-2021-31365?
CVE-2021-31365 affects Juniper Networks Junos OS, Juniper Networks Junos OS, Juniper Networks Junos OS.
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