SB2021071527 - Security restrictions bypass in Junos OS
Published: July 15, 2021
Security Bulletin ID
SB2021071527
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Adjecent network
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2021-0289)
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.