CVE-2021-0224

high-risk
Published 2021-04-22

A vulnerability in the handling of internal resources necessary to bring up a large number of Layer 2 broadband remote access subscriber (BRAS) nodes in Juniper Networks Junos OS can cause the Access Node Control Protocol daemon (ANCPD) to crash and restart, leading to a Denial of Service (DoS) condition. Continued processing of spoofed subscriber nodes will create a sustained Denial of Service (DoS) condition. When the number of subscribers attempting to connect exceeds the configured maximum-discovery-table-entries value, the subscriber fails to map to an internal neighbor entry, causing the ANCPD process to crash. This issue affects Juniper Networks Junos OS: All versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R3-S8; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2; 20.3 versions prior to 20.3R2.

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
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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)

54
/ 100
high-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 33/34 · Critical