CVE-2021-0287

Summary

In a Segment Routing ISIS (SR-ISIS)/MPLS environment, on Juniper Networks Junos OS and Junos OS Evolved devices, configured with ISIS Flexible Algorithm for Segment Routing and sensor-based statistics, a flap of a ISIS link in the network, can lead to a routing process daemon (RPD) crash and restart, causing a Denial of Service (DoS). Continued link flaps will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: 19.4 versions prior to 19.4R1-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R2-S2, 20.2R3; 20.3 versions prior to 20.3R2; Juniper Networks Junos OS Evolved: 20.3-EVO versions prior to 20.3R2-EVO; 20.4-EVO versions prior to 20.4R2-EVO. This issue does not affect: Juniper Networks Junos OS releases prior to 19.4R1. Juniper Networks Junos OS Evolved releases prior to 19.4R1-EVO.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OSunspecified < 19.4R1unaffected
Juniper NetworksJunos OS19.4R1 < 19.4*affected
Juniper NetworksJunos OS20.1 < 20.1R2-S1, 20.1R3affected
Juniper NetworksJunos OS20.2 < 20.2R2-S2, 20.2R3affected
Juniper NetworksJunos OS20.3 < 20.3R2affected
Juniper NetworksJunos OS Evolvedunspecified < 19.4R1-EVOunaffected
Juniper NetworksJunos OS Evolved19.4R1-EVO < 19.4*affected
Juniper NetworksJunos OS Evolved20.1R1-EVO < 20.1*affected
Juniper NetworksJunos OS Evolved20.2R1-EVO < 20.2*affected
Juniper NetworksJunos OS Evolved20.3 < 20.3R2-EVOaffected
Juniper NetworksJunos OS Evolved20.4 < 20.4R2-EVOaffected

Weaknesses

  • CWE-754: CWE-754 Improper Check for Unusual or Exceptional Conditions

Workarounds

Disabling IS-IS Flexible Algorithm for Segment Routing or sensor-based statistics will mitigate this issue.

ADP Enrichment

CVE Program Container

Additional References

References