CVE-2021-31369

On MX Series platforms with MS-MPC/MS-MIC, an Allocation of Resources Without Limits or Throttling vulnerability in Juniper Networks Junos OS allows an unauthenticated network attacker to cause a partial Denial of Service (DoS) with a high rate of specific traffic. If a Class of Service (CoS) rule is attached to the service-set and a high rate of specific traffic is processed by this service-set, for some of the other traffic which has services applied and is being processed by this MS-MPC/MS-MIC drops will be observed. Continued receipted of this high rate of specific traffic will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on MX Series with MS-MPC/MS-MIC: All versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 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-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; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.

• CWE-770
• CWE-770

• https://kb.juniper.net/JSA11231Vendor Advisory
• https://kb.juniper.net/JSA11231Vendor Advisory

Published

Oct 19, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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