CVE-2021-31383

Junos OS and Junos OS Evolved: In Point to MultiPoint (P2MP) scenarios receipt of various crafted packets causes RPD to core.

Description

In Point to MultiPoint (P2MP) scenarios within established sessions between network or adjacent neighbors the improper use of a source to destination copy write operation combined with a Stack-based Buffer Overflow on certain specific packets processed by the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved sent by a remote unauthenticated network attacker causes the RPD to crash causing a Denial of Service (DoS). Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R1. Juniper Networks Junos OS Evolved 20.1 versions prior to 20.1R3-EVO; 20.2 versions prior to 20.2R3-EVO; 20.3 versions prior to 20.3R2-EVO.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS: 19.2R3-S2, 19.3R2-S6, 19.3R3-S2, 19.4R1-S4, 19.4R2-S4, 19.4R3-S3, 20.1R2-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases. Junos OS Evolved: 20.1R3-EVO, 20.2R3-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.

Workaround:

  • For Junos OS you can remove the traffic-statistics from the configuration to work around this issue. [protoccols ldp traffic-statistics {sensor-based-stats;}] For Junos OS Evolved there are no viable workarounds for this issue.

Categories

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.46%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11251 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-31383?
CVE-2021-31383 has been scored as a high severity vulnerability.
How to fix CVE-2021-31383?
To fix CVE-2021-31383: The following software releases have been updated to resolve this specific issue: Junos OS: 19.2R3-S2, 19.3R2-S6, 19.3R3-S2, 19.4R1-S4, 19.4R2-S4, 19.4R3-S3, 20.1R2-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases. Junos OS Evolved: 20.1R3-EVO, 20.2R3-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.
Is CVE-2021-31383 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-31383 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-2021-31383?
CVE-2021-31383 affects Juniper Networks Junos OS, Juniper Networks Junos OS Evolved.
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