high
8.6
CWE
401 710
Advisory Published
Updated

CVE-2020-1603: Junos OS: Improper handling of specific IPv6 packets sent by clients eventually kernel crash (vmcore) the device.

First published: Wed Jan 15 2020(Updated: )

Specific IPv6 packets sent by clients processed by the Routing Engine (RE) are improperly handled. These IPv6 packets are designed to be blocked by the RE from egressing the RE. Instead, the RE allows these specific IPv6 packets to egress the RE, at which point a mbuf memory leak occurs within the Juniper Networks Junos OS device. This memory leak eventually leads to a kernel crash (vmcore), or the device hanging and requiring a power cycle to restore service, creating a Denial of Service (DoS) condition. During the time where mbufs are rising, yet not fully filled, some traffic from client devices may begin to be black holed. To be black holed, this traffic must match the condition where this traffic must be processed by the RE. Continued receipt and attempted egress of these specific IPv6 packets from the Routing Engine (RE) will create an extended Denial of Service (DoS) condition. Scenarios which have been observed are: 1. In a single chassis, single RE scenario, the device will hang without vmcore, or a vmcore may occur and then hang. In this scenario the device needs to be power cycled. 2. In a single chassis, dual RE scenario, the device master RE will fail over to the backup RE. In this scenario, the master and the backup REs need to be reset from time to time when they vmcore. There is no need to power cycle the device. 3. In a dual chassis, single RE scenario, the device will hang without vmcore, or a vmcore may occur and then hang. In this scenario, the two chassis' design relies upon some type of network level redundancy - VRRP, GRES, NSR, etc. - 3.a In a commanded switchover, where nonstop active routing (NSR) is enabled no session loss is observed. 4. In a dual chassis, dual chassis scenario, rely upon the RE to RE failover as stated in the second scenario. In the unlikely event that the device does not switch RE to RE gracefully, then the fallback position is to the network level services scenario in the third scenario. This issue affects: Juniper Networks Junos OS 16.1 versions prior to 16.1R7-S6; 16.1 version 16.1X70-D10 and later; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R1-S9, 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D50, 18.2X75-D410; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S6, 18.4R2-S2, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S2, 19.2R2. This issue does not affect releases prior to Junos OS 16.1R1.

Credit: sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
Junos OS Evolved=16.1
Junos OS Evolved=16.1-r1
Junos OS Evolved=16.1-r2
Junos OS Evolved=16.1-r3
Junos OS Evolved=16.1-r3-s10
Junos OS Evolved=16.1-r4
Junos OS Evolved=16.1-r5-s4
Junos OS Evolved=16.1-r6-s1
Junos OS Evolved=16.1-r7
Junos OS Evolved=16.1-r7-s2
Junos OS Evolved=16.1-r7-s3
Junos OS Evolved=16.1-r7-s4
Junos OS Evolved=16.1-r7-s5
Junos OS Evolved=16.1x70
Junos OS Evolved=16.2
Junos OS Evolved=16.2-r1
Junos OS Evolved=16.2-r2
Junos OS Evolved=16.2-r2-s1
Junos OS Evolved=16.2-r2-s10
Junos OS Evolved=16.2-r2-s2
Junos OS Evolved=16.2-r2-s5
Junos OS Evolved=16.2-r2-s6
Junos OS Evolved=16.2-r2-s7
Junos OS Evolved=16.2-r2-s8
Junos OS Evolved=16.2-r2-s9
Junos OS Evolved=17.1
Junos OS Evolved=17.1-r1
Junos OS Evolved=17.1-r2-s1
Junos OS Evolved=17.1-r2-s10
Junos OS Evolved=17.1-r2-s2
Junos OS Evolved=17.1-r2-s3
Junos OS Evolved=17.1-r2-s4
Junos OS Evolved=17.1-r2-s5
Junos OS Evolved=17.1-r2-s6
Junos OS Evolved=17.1-r2-s7
Junos OS Evolved=17.1-r2-s9
Junos OS Evolved=17.1-r3
Junos OS Evolved=17.2
Junos OS Evolved=17.2-r1-s2
Junos OS Evolved=17.2-r1-s4
Junos OS Evolved=17.2-r1-s7
Junos OS Evolved=17.2-r1-s8
Junos OS Evolved=17.2-r2-s6
Junos OS Evolved=17.2-r2-s7
Junos OS Evolved=17.2-r3
Junos OS Evolved=17.2-r3-s1
Junos OS Evolved=17.2-r3-s2
Junos OS Evolved=17.3
Junos OS Evolved=17.3-r1-s1
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-r3-s1
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=17.4
Junos OS Evolved=17.4-r1
Junos OS Evolved=17.4-r1-s1
Junos OS Evolved=17.4-r1-s2
Junos OS Evolved=17.4-r1-s4
Junos OS Evolved=17.4-r1-s6
Junos OS Evolved=17.4-r1-s7
Junos OS Evolved=17.4-r2
Junos OS Evolved=17.4-r2-s1
Junos OS Evolved=17.4-r2-s2
Junos OS Evolved=17.4-r2-s3
Junos OS Evolved=17.4-r2-s4
Junos OS Evolved=17.4-r2-s5
Junos OS Evolved=17.4-r2-s6
Junos OS Evolved=17.4-r2-s7
Junos OS Evolved=17.4-r2-s8
Junos OS Evolved=18.1
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-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=18.2
Junos OS Evolved=18.2-r1-s5
Junos OS Evolved=18.2-r2-s1
Junos OS Evolved=18.2-r2-s2
Junos OS Evolved=18.2-r2-s3
Junos OS Evolved=18.2-r2-s4
Junos OS Evolved=18.2-r3
Junos OS Evolved=18.2-r3-s1
Junos OS Evolved=18.2x75
Junos OS Evolved=18.2x75-d20
Junos OS Evolved=18.2x75-d40
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-r2
Junos OS Evolved=18.3-r2-s1
Junos OS Evolved=18.4
Junos OS Evolved=18.4-r1
Junos OS Evolved=18.4-r1-s1
Junos OS Evolved=18.4-r1-s2
Junos OS Evolved=18.4-r1-s3
Junos OS Evolved=18.4-r1-s4
Junos OS Evolved=18.4-r1-s5
Junos OS Evolved=18.4-r2
Junos OS Evolved=18.4-r2-s1
Junos OS Evolved=19.1-r1
Junos OS Evolved=19.1-r1-s1
Junos OS Evolved=19.1-r1-s2
Junos OS Evolved=19.2-r1
Junos OS Evolved=19.2-r1-s1

Remedy

The following software releases have been updated to resolve this specific issue: 16.1R7-S6, 16.2R2-S11, 17.1R2-S11, 17.1R3-S1, 17.2R1-S9, 17.2R2-S8, 17.2R3-S3, 17.3R3-S6, 17.4R2-S9, 17.4R3, 18.1R3-S7, 18.2R3-S2, 18.2X75-D50, 18.2X75-D410, 18.3R1-S6, 18.3R2-S2, 18.3R3, 18.4R1-S6, 18.4R2-S2, 18.4R3, 19.1R1-S3, 19.1R2, 19.2R1-S2, 19.2R2, 19.3R1, and all subsequent releases.

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2020-1603?

    CVE-2020-1603 is rated with a high severity due to its potential impact on system stability and security.

  • How do I fix CVE-2020-1603?

    To address CVE-2020-1603, apply the recommended patches or updates provided by Juniper for the affected Junos versions.

  • Which versions of Junos are affected by CVE-2020-1603?

    CVE-2020-1603 affects several versions of Junos, including versions 16.1, 16.2, 17.1, 17.2, 17.3, 17.4, and 18.1.

  • What will happen if CVE-2020-1603 is exploited?

    Exploiting CVE-2020-1603 could lead to a memory leak, potentially destabilizing the device and impacting performance.

  • Is there a workaround for CVE-2020-1603?

    There are no official workarounds for CVE-2020-1603, making it crucial to update to patched versions as soon as possible.

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