CVE-2021-0224

Junos OS: ANCPD core when hitting maximum-discovery-table-entries limit

Description

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.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R2-S13, 18.2R3-S8, 18.4R1-S8, 18.4R3-S8, 19.1R3-S4, 19.2R3-S2, 19.3R3-S1, 19.4R3-S1, 20.1R2, 20.1R3, 20.2R2, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases.

Workaround:

  • There are no viable workarounds for this issue.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.08%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11119 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-0224?
CVE-2021-0224 has been scored as a medium severity vulnerability.
How to fix CVE-2021-0224?
To fix CVE-2021-0224: The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R2-S13, 18.2R3-S8, 18.4R1-S8, 18.4R3-S8, 19.1R3-S4, 19.2R3-S2, 19.3R3-S1, 19.4R3-S1, 20.1R2, 20.1R3, 20.2R2, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases.
Is CVE-2021-0224 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-0224 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-0224?
CVE-2021-0224 affects Juniper Networks Junos OS.
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