CVE-2021-0287

moderate-risk
Published 2021-07-15

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.

Do I need to act?

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0.08% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
6
CVSS 6.5/10 Medium
ADJACENT_NETWORK / LOW complexity

Affected Vendors

References (2)

43
/ 100
moderate-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 22/34 · High