high
7.5
CWE
754
Advisory Published
Updated

CVE-2021-31351: Junos OS: MX Series: Receipt of specific packet on MS-MPC/MS-MIC causes line card reset

First published: Tue Oct 19 2021(Updated: )

An Improper Check for Unusual or Exceptional Conditions in packet processing on the MS-MPC/MS-MIC utilized by Juniper Networks Junos OS allows a malicious attacker to send a specific packet, triggering the MS-MPC/MS-MIC to reset, causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects specific versions of Juniper Networks Junos OS on MX Series: 17.3R3-S11; 17.4R2-S13; 17.4R3 prior to 17.4R3-S5; 18.1R3-S12; 18.2R2-S8, 18.2R3-S7, 18.2R3-S8; 18.3R3-S4; 18.4R3-S7; 19.1R3-S4, 19.1R3-S5; 19.2R1-S6; 19.3R3-S2; 19.4R2-S4, 19.4R2-S5; 19.4R3-S2; 20.1R2-S1; 20.2R2-S2, 20.2R2-S3, 20.2R3; 20.3R2, 20.3R2-S1; 20.4R1, 20.4R1-S1, 20.4R2; 21.1R1; This issue does not affect any version of Juniper Networks Junos OS prior to 15.1X49-D240;

Credit: sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
Juniper JUNOS=17.3-r3-s11
Juniper JUNOS=17.4-r2-s13
Juniper JUNOS=17.4-r3
Juniper JUNOS=17.4-r3-s1
Juniper JUNOS=17.4-r3-s2
Juniper JUNOS=17.4-r3-s3
Juniper JUNOS=17.4-r3-s4
Juniper JUNOS=18.1-r3-s12
Juniper JUNOS=18.2-r2-s8
Juniper JUNOS=18.2-r3-s7
Juniper JUNOS=18.2-r3-s8
Juniper JUNOS=18.3-r3-s4
Juniper JUNOS=18.4-r3-s7
Juniper JUNOS=19.1-r3-s4
Juniper JUNOS=19.1-r3-s5
Juniper JUNOS=19.2-r1-s6
Juniper JUNOS=19.3-r3-s2
Juniper JUNOS=19.4-r2-s4
Juniper JUNOS=19.4-r2-s5
Juniper JUNOS=19.4-r3-s2
Juniper JUNOS=20.1-r2-s1
Juniper JUNOS=20.2-r2-s2
Juniper JUNOS=20.2-r2-s3
Juniper JUNOS=20.2-r3
Juniper JUNOS=20.3-r2
Juniper JUNOS=20.3-r2-s1
Juniper JUNOS=20.4-r1
Juniper JUNOS=20.4-r1-s1
Juniper JUNOS=20.4-r2
Juniper JUNOS=21.1-r1
Juniper Mx10
Juniper Mx10000
Juniper Mx10003
Juniper Mx10008
Juniper Mx10016
Juniper Mx104
Juniper Mx150
Juniper Mx2008
Juniper Mx2010
Juniper Mx2020
Juniper Mx204
Juniper Mx240
Juniper Mx40
Juniper Mx480
Juniper Mx5
Juniper Mx80
Juniper Mx960

Remedy

The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R3-S5, 18.1R3-S13, 18.3R3-S5, 18.4R3-S8, 19.1R3-S6, 19.2R1-S7, 19.2R3-S2, 19.3R2-S6, 19.3R3-S3, 19.4R3-S3, 20.1R2-S2, 20.1R3, 20.2R3-S1, 20.3R3, 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, and all subsequent releases. Note: Only those releases listed in the PROBLEM section above are affected. This fix has also been proactively committed into other releases that are not vulnerable to this issue.

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Reference Links

Frequently Asked Questions

  • What is CVE-2021-31351?

    CVE-2021-31351 is a vulnerability in Juniper Networks Junos OS that allows a malicious attacker to cause a Denial of Service (DoS) by sending a specific packet.

  • Which versions of Juniper Junos are affected by CVE-2021-31351?

    Juniper Junos versions 17.3-r3-s11 to 20.4-r2 are affected by CVE-2021-31351.

  • How severe is CVE-2021-31351?

    CVE-2021-31351 has a severity rating of 7.5, which is considered high.

  • How can I fix CVE-2021-31351?

    To fix CVE-2021-31351, you should upgrade to a non-vulnerable version of Juniper Junos OS. Refer to the Juniper Networks advisory for more information.

  • Where can I find more information about CVE-2021-31351?

    You can find more information about CVE-2021-31351 on the Juniper Networks Knowledge Base at the provided reference link.

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