Out-of-Bounds Write in Juniper Networks Junos OS SNMP Daemon

Executive Summary

This vulnerability is an Out-of-bounds Write in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved. An authenticated network-based attacker can send specific valid SNMPv3 queries that trigger a memory leak in the snmpd process.

Over time, if these queries are continuously received, the memory used by the snmpd process will be exhausted, causing the process to crash and restart.

This impacts the ability to monitor the system via SNMP because the snmpd process is responsible for handling SNMP requests.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by monitoring the memory usage of the snmpd process on affected Juniper devices.

You can use the following command to monitor the memory usage of the snmpd process:

• show system processes extensive | match snmpd

Continuous increase in memory usage of the snmpd process may indicate exploitation attempts of this vulnerability.

Useful 0 Not Useful 0

Impact Analysis

The vulnerability can lead to memory exhaustion of the snmpd process, causing it to crash and restart repeatedly.

This results in a loss of SNMP monitoring capability on the affected device, which can hinder system monitoring and management.

If SNMP monitoring is critical for your network operations, this could lead to delayed detection of issues or outages.

Useful 0 Not Useful 0

Mitigation Strategies

To mitigate this vulnerability, you should upgrade your Junos OS or Junos OS Evolved to a fixed version that is not affected by the issue. Specifically, ensure your system is running one of the following versions or later:

• For Junos OS: 21.2R3-S8 or later, 21.4R3-S7 or later, 22.1R3-S6 or later, 22.2R3-S4 or later, 22.3R3-S3 or later, 22.4R3-S2 or later, 23.2R2 or later, or 23.4R2 or later.
• For Junos OS Evolved: 21.2R3-S8-EVO or later, 21.4R3-S7-EVO or later, 22.2R3-S4-EVO or later, 22.3R3-S3-EVO or later, 23.2R2-EVO or later, or 23.4R2-EVO or later.

Additionally, monitor the memory usage of the snmpd process using the command: show system processes extensive | match snmpd to detect abnormal memory consumption that could indicate exploitation attempts.

Useful 0 Not Useful 0