SB2021071527 - Security restrictions bypass in Junos OS

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Main Vulnerability Database SB2021071527

SB2021071527 - Security restrictions bypass in Junos OS

Published: July 15, 2021

Security Bulletin ID SB2021071527
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Adjecent network
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2021-0289)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to a race condition between the Device Control Daemon (DCD) and firewall process (dfwd) daemons of Juniper Networks Junos OS, when user-defined ARP Policer is configured and applied on one or more Aggregated Ethernet (AE) interface units. A remote attacker on the local network can bypass the user-defined ARP Policer.


Remediation

Install update from vendor's website.

References