medium
5.3
CWE
200
Advisory Published
Updated

CVE-2021-31371: Junos OS: QFX5000 Series: Traffic from the network internal to the device (128.0.0.0) may be forwarded to egress interfaces.

First published: Wed Oct 13 2021(Updated: )

Juniper Networks Junos OS uses the 128.0.0.0/2 subnet for internal communications between the RE and PFEs. It was discovered that packets utilizing these IP addresses may egress an QFX5000 Series switch, leaking configuration information such as heartbeats, kernel versions, etc. out to the Internet, leading to an information exposure vulnerability. This issue affects Juniper Networks Junos OS on QFX5110, QFX5120, QFX5200, QFX5210 Series, and QFX5100 with QFX 5e Series image installed: All versions prior to 17.3R3-S12; 18.1 versions prior to 18.1R3-S13; 18.3 versions prior to 18.3R3-S5; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 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 21.1R1-S1, 21.1R2;

Credit: sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
Junos OS Evolved<=17.2
Junos OS Evolved=17.3
Junos OS Evolved=17.3-r1
Junos OS Evolved=17.3-r1-s1
Junos OS Evolved=17.3-r1-s4
Junos OS Evolved=17.3-r2
Junos OS Evolved=17.3-r2-s1
Junos OS Evolved=17.3-r2-s2
Junos OS Evolved=17.3-r2-s3
Junos OS Evolved=17.3-r2-s4
Junos OS Evolved=17.3-r2-s5
Junos OS Evolved=17.3-r3
Junos OS Evolved=17.3-r3-s1
Junos OS Evolved=17.3-r3-s10
Junos OS Evolved=17.3-r3-s11
Junos OS Evolved=17.3-r3-s2
Junos OS Evolved=17.3-r3-s3
Junos OS Evolved=17.3-r3-s4
Junos OS Evolved=17.3-r3-s5
Junos OS Evolved=17.3-r3-s6
Junos OS Evolved=17.3-r3-s7
Junos OS Evolved=17.3-r3-s8
Junos OS Evolved=17.3-r3-s9
Junos OS Evolved=18.1
Junos OS Evolved=18.1-r1
Junos OS Evolved=18.1-r2
Junos OS Evolved=18.1-r2-s1
Junos OS Evolved=18.1-r2-s2
Junos OS Evolved=18.1-r2-s4
Junos OS Evolved=18.1-r3
Junos OS Evolved=18.1-r3-s1
Junos OS Evolved=18.1-r3-s10
Junos OS Evolved=18.1-r3-s11
Junos OS Evolved=18.1-r3-s12
Junos OS Evolved=18.1-r3-s2
Junos OS Evolved=18.1-r3-s3
Junos OS Evolved=18.1-r3-s4
Junos OS Evolved=18.1-r3-s5
Junos OS Evolved=18.1-r3-s6
Junos OS Evolved=18.1-r3-s7
Junos OS Evolved=18.1-r3-s8
Junos OS Evolved=18.1-r3-s9
Junos OS Evolved=18.3
Junos OS Evolved=18.3-r1
Junos OS Evolved=18.3-r1-s1
Junos OS Evolved=18.3-r1-s2
Junos OS Evolved=18.3-r1-s3
Junos OS Evolved=18.3-r1-s4
Junos OS Evolved=18.3-r1-s5
Junos OS Evolved=18.3-r1-s6
Junos OS Evolved=18.3-r2
Junos OS Evolved=18.3-r2-s1
Junos OS Evolved=18.3-r2-s2
Junos OS Evolved=18.3-r2-s3
Junos OS Evolved=18.3-r2-s4
Junos OS Evolved=18.3-r3
Junos OS Evolved=18.3-r3-s1
Junos OS Evolved=18.3-r3-s2
Junos OS Evolved=18.3-r3-s3
Junos OS Evolved=18.3-r3-s4
Junos OS Evolved=19.1
Junos OS Evolved=19.1-r1
Junos OS Evolved=19.1-r1-s1
Junos OS Evolved=19.1-r1-s2
Junos OS Evolved=19.1-r1-s3
Junos OS Evolved=19.1-r1-s4
Junos OS Evolved=19.1-r1-s5
Junos OS Evolved=19.1-r1-s6
Junos OS Evolved=19.1-r2
Junos OS Evolved=19.1-r2-s1
Junos OS Evolved=19.1-r2-s2
Junos OS Evolved=19.1-r2-s3
Junos OS Evolved=19.1-r3
Junos OS Evolved=19.1-r3-s1
Junos OS Evolved=19.1-r3-s2
Junos OS Evolved=19.1-r3-s3
Junos OS Evolved=19.1-r3-s4
Junos OS Evolved=19.1-r3-s5
Junos OS Evolved=19.2
Junos OS Evolved=19.2-r1
Junos OS Evolved=19.2-r1-s1
Junos OS Evolved=19.2-r1-s2
Junos OS Evolved=19.2-r1-s3
Junos OS Evolved=19.2-r1-s4
Junos OS Evolved=19.2-r1-s5
Junos OS Evolved=19.2-r1-s6
Junos OS Evolved=19.2-r2
Junos OS Evolved=19.2-r2-s1
Junos OS Evolved=19.2-r3
Junos OS Evolved=19.2-r3-s1
Junos OS Evolved=19.2-r3-s2
Junos OS Evolved=19.3
Junos OS Evolved=19.3-r1
Junos OS Evolved=19.3-r1-s1
Junos OS Evolved=19.3-r2
Junos OS Evolved=19.3-r2-s1
Junos OS Evolved=19.3-r2-s2
Junos OS Evolved=19.3-r2-s3
Junos OS Evolved=19.3-r2-s4
Junos OS Evolved=19.3-r2-s5
Junos OS Evolved=19.3-r3
Junos OS Evolved=19.3-r3-s1
Junos OS Evolved=19.3-r3-s2
Junos OS Evolved=19.4-r1
Junos OS Evolved=19.4-r1-s1
Junos OS Evolved=19.4-r1-s2
Junos OS Evolved=19.4-r1-s3
Junos OS Evolved=19.4-r2
Junos OS Evolved=19.4-r2-s1
Junos OS Evolved=19.4-r2-s2
Junos OS Evolved=19.4-r2-s3
Junos OS Evolved=19.4-r2-s4
Junos OS Evolved=19.4-r2-s5
Junos OS Evolved=19.4-r3
Junos OS Evolved=19.4-r3-s1
Junos OS Evolved=19.4-r3-s2
Junos OS Evolved=19.4-r3-s3
Junos OS Evolved=19.4-r3-s4
Junos OS Evolved=20.1-r1
Junos OS Evolved=20.1-r1-s1
Junos OS Evolved=20.1-r1-s2
Junos OS Evolved=20.1-r1-s3
Junos OS Evolved=20.1-r1-s4
Junos OS Evolved=20.1-r2
Junos OS Evolved=20.1-r2-s1
Junos OS Evolved=20.1-r3
Junos OS Evolved=20.2-r1
Junos OS Evolved=20.2-r1-s1
Junos OS Evolved=20.2-r1-s2
Junos OS Evolved=20.2-r1-s3
Junos OS Evolved=20.2-r2
Junos OS Evolved=20.2-r2-s1
Junos OS Evolved=20.2-r2-s2
Junos OS Evolved=20.2-r2-s3
Junos OS Evolved=20.2-r3
Junos OS Evolved=20.2-r3-s1
Junos OS Evolved=20.3-r1
Junos OS Evolved=20.3-r1-s1
Junos OS Evolved=20.3-r2
Junos OS Evolved=20.3-r2-s1
Junos OS Evolved=20.3-r3
Junos OS Evolved=20.4-r1
Junos OS Evolved=20.4-r1-s1
Junos OS Evolved=20.4-r2
Junos OS Evolved=21.1-r1
Juniper QFX5100
Juniper QFX5110
Juniper QFX5120
Juniper QFX5200-32C
Juniper QFX5210-64C

Remedy

The following software releases have been updated to resolve this specific issue: 17.3R3-S12, 18.1R3-S13, 18.3R3-S5, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R1-S4, 19.4R3-S5, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, and all subsequent releases.

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-31371?

    CVE-2021-31371 has a high severity rating due to the potential exposure of sensitive configuration information.

  • How do I fix CVE-2021-31371?

    To remediate CVE-2021-31371, upgrade to a fixed version of Junos OS that mitigates this vulnerability.

  • Which versions of Junos OS are affected by CVE-2021-31371?

    Junos OS versions prior to 17.3 and versions including 17.3, 18.1, and 19.1 are affected by CVE-2021-31371.

  • What type of exposure does CVE-2021-31371 involve?

    CVE-2021-31371 can lead to the unintentional egress of packets carrying internal configuration data.

  • Is my hardware affected by CVE-2021-31371 if I use QFX5000 Series switches?

    Yes, if using QFX5000 Series switches with affected Junos OS versions, they are susceptible to CVE-2021-31371.

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