A release of illegal memory vulnerability in the snmpd daemon of Juniper Networks Junos OS, Junos OS Evolved allows an attacker to halt the snmpd daemon causing a sustained Denial of Service (DoS) to the service until it is manually restarted.

This issue impacts any version of SNMP – v1,v2, v3

This issue affects:
Juniper Networks Junos OS

• 12.3 versions prior to 12.3R12-S20;
• 15.1 versions prior to 15.1R7-S11;
• 18.3 versions prior to 18.3R3-S6;
• 18.4 versions prior to 18.4R2-S9, 18.4R3-S10;
• 19.1 versions prior to 19.1R2-S3, 19.1R3-S7;
• 19.2 versions prior to 19.2R1-S8, 19.2R3-S4;
• 19.3 versions prior to 19.3R3-S4;
• 19.4 versions prior to 19.4R2-S5, 19.4R3-S6;
• 20.1 versions prior to 20.1R3-S2;
• 20.2 versions prior to 20.2R3-S3;
• 20.3 versions prior to 20.3R3-S1;
• 20.4 versions prior to 20.4R3;
• 21.1 versions prior to 21.1R2-S2, 21.1R3;
• 21.2 versions prior to 21.2R1-S2, 21.2R2.

Juniper Networks Junos OS Evolved

• 21.2 versions prior to 21.2R3-EVO;
• 21.3 versions prior to 21.3R2-EVO.

The following minimal configuration is needed:
[snmp community 'community-name"]  using a Read Write (RW) Community

Read Only (RO) communities are not impacted by this issue.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was discovered during external security research.

This issue has been assigned  CVE-2022-22177 .

The following software releases have been updated to resolve this specific issue:

Junos OS: 12.3R12-S20, 15.1R7-S11, 18.3R3-S6, 18.4R2-S9, 18.4R3-S10, 19.1R2-S3, 19.1R3-S7, 19.2R1-S8, 19.2R3-S4, 19.3R3-S4, 19.4R2-S5, 19.4R3-S6, 20.1R3-S2, 20.2R3-S3, 20.3R3-S1, 20.4R3, 21.1R2-S2, 21.1R3, 21.2R1-S2, 21.2R2, 21.3R1, and all subsequent releases.

Junos OS Evolved: 21.2R3-EVO, 21.3R2-EVO, 21.4R1-EVO, and all subsequent releases.

This issue is being tracked as  1613874 .

There are no workarounds for this issue.

For V1, V2 you can reduce the risk of exploitation by configuring the client-list to limit access to network management system (NMS) machines.

See the Network Management and Monitoring Guide for further instructions.

example:

[snmp client-list client-list-name "ip-addresses";]

For V3 you can reduce the risk of exploitation by configuring SNMP security to trusted devices only.

For any release of SNMP you can reduce the risk of exploitation by implementing source and destination IP filter rules as well as using Read Only communities where possible.

Regardless of these risk reduction methods, an attacker able to spoof trusted IP addresses can send the attack to an exposed and reachable SNMP RW community.