CVE-2023-36842: Junos OS: jdhcpd will hang on receiving a specific DHCP packet

Published Jan 12, 2024
·
Updated

An Improper Check for Unusual or Exceptional Conditions vulnerability in Juniper DHCP Daemon (jdhcpd) of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause the jdhcpd to consume all the CPU cycles resulting in a Denial of Service (DoS).

On Junos OS devices with forward-snooped-client configured, if an attacker sends a specific DHCP packet to a non-configured interface, this will cause an infinite loop. The DHCP process will have to be restarted to recover the service.

This issue affects:

Juniper Networks Junos OS

All versions earlier than 20.4R3-S9; 21.2 versions earlier than 21.2R3-S7; 21.3 versions earlier than 21.3R3-S5; 21.4 versions earlier than 21.4R3-S5; 22.1 versions earlier than 22.1R3-S4; 22.2 versions earlier than 22.2R3-S3; 22.3 versions earlier than 22.3R3-S2; 22.4 versions earlier than 22.4R2-S2, 22.4R3; 23.2 versions earlier than 23.2R2.

Affected Software

93 affected components
Juniper Junos<20.4
Juniper Junos=20.4
Juniper Junos=20.4-r1
Juniper Junos=20.4-r1-s1
Juniper Junos=20.4-r2
Juniper Junos=20.4-r2-s1
Juniper Junos=20.4-r2-s2
Juniper Junos=20.4-r3
Juniper Junos=20.4-r3-s1
Juniper Junos=20.4-r3-s2
Juniper Junos=20.4-r3-s3
Juniper Junos=20.4-r3-s4
Juniper Junos=20.4-r3-s5
Juniper Junos=20.4-r3-s6
Juniper Junos=20.4-r3-s7
Juniper Junos=20.4-r3-s8
Juniper Junos=21.2
Juniper Junos=21.2-r1
Juniper Junos=21.2-r1-s1
Juniper Junos=21.2-r1-s2
Juniper Junos=21.2-r2
Juniper Junos=21.2-r2-s1
Juniper Junos=21.2-r2-s2
Juniper Junos=21.2-r3
Juniper Junos=21.2-r3-s1
Juniper Junos=21.2-r3-s2
Juniper Junos=21.2-r3-s3
Juniper Junos=21.2-r3-s4
Juniper Junos=21.2-r3-s5
Juniper Junos=21.2-r3-s6
Juniper Junos=21.3
Juniper Junos=21.3-r1
Juniper Junos=21.3-r1-s1
Juniper Junos=21.3-r1-s2
Juniper Junos=21.3-r2
Juniper Junos=21.3-r2-s1
Juniper Junos=21.3-r2-s2
Juniper Junos=21.3-r3
Juniper Junos=21.3-r3-s1
Juniper Junos=21.3-r3-s2
Juniper Junos=21.3-r3-s3
Juniper Junos=21.3-r3-s4
Juniper Junos=21.4
Juniper Junos=21.4-r1
Juniper Junos=21.4-r1-s1
Juniper Junos=21.4-r1-s2
Juniper Junos=21.4-r2
Juniper Junos=21.4-r2-s1
Juniper Junos=21.4-r2-s2
Juniper Junos=21.4-r3
Juniper Junos=21.4-r3-s1
Juniper Junos=21.4-r3-s2
Juniper Junos=21.4-r3-s3
Juniper Junos=21.4-r3-s4
Juniper Junos=22.1
Juniper Junos=22.1-r1
Juniper Junos=22.1-r1-s1
Juniper Junos=22.1-r1-s2
Juniper Junos=22.1-r2
Juniper Junos=22.1-r2-s1
Juniper Junos=22.1-r2-s2
Juniper Junos=22.1-r3
Juniper Junos=22.1-r3-s1
Juniper Junos=22.1-r3-s2
Juniper Junos=22.1-r3-s3
Juniper Junos=22.2
Juniper Junos=22.2-r1
Juniper Junos=22.2-r1-s1
Juniper Junos=22.2-r1-s2
Juniper Junos=22.2-r2
Juniper Junos=22.2-r2-s1
Juniper Junos=22.2-r2-s2
Juniper Junos=22.2-r3
Juniper Junos=22.2-r3-s1
Juniper Junos=22.2-r3-s2
Juniper Junos=22.3
Juniper Junos=22.3-r1
Juniper Junos=22.3-r1-s1
Juniper Junos=22.3-r1-s2
Juniper Junos=22.3-r2
Juniper Junos=22.3-r2-s1
Juniper Junos=22.3-r2-s2
Juniper Junos=22.3-r3
Juniper Junos=22.3-r3-s1
Juniper Junos=22.4
Juniper Junos=22.4-r1
Juniper Junos=22.4-r1-s1
Juniper Junos=22.4-r1-s2
Juniper Junos=22.4-r2
Juniper Junos=22.4-r2-s1
Juniper Junos=23.2-r1
Juniper Junos=23.2-r1-s1
Juniper Junos=23.2-r1-s2

Remediation

Information

The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S2, 22.4R2-S2, 22.4R3, 23.2R1-S2, 23.2R2, 23.4R1, and all subsequent releases.

Event History

Jan 12, 2024
CVE Published
via MITRE·12:48 AM
Data Sourced
via MITRE·12:48 AM
RemedyDescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2023-36842?

CVE-2023-36842 is classified as a high-severity vulnerability leading to Denial of Service (DoS).

2

How do I fix CVE-2023-36842?

Fixing CVE-2023-36842 involves upgrading affected Junos OS versions to the latest secure release provided by Juniper Networks.

3

Which versions of Junos OS are affected by CVE-2023-36842?

CVE-2023-36842 affects Junos OS versions up to 20.4 and various versions from 21.2 through 23.2, including specific releases.

4

Can CVE-2023-36842 be exploited remotely?

Yes, CVE-2023-36842 can be exploited by an adjacent, unauthenticated attacker over the network.

5

What impact does CVE-2023-36842 have on systems?

CVE-2023-36842 may cause the Juniper DHCP Daemon to consume all CPU cycles, resulting in a Denial of Service on the device.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203