An Improper Input Validation vulnerability in Juniper Tunnel Driver (jtd) and ICMP module of Juniper Networks Junos OS Evolved allows an unauthenticated attacker within the MPLS administrative domain to send specifically crafted packets to the Routing Engine (RE) to cause a Denial of Service (DoS). 

When specifically crafted transit MPLS IPv4 packets are received by the Packet Forwarding Engine (PFE), these packets are internally forwarded to the RE. Continued receipt of these packets may create a sustained Denial of Service (DoS) condition.

This issue affects Juniper Networks Junos OS:

• All versions before 21.2R3-S8-EVO;
• from 21.4-EVO before 21.4R3-S6-EVO;
• from 22.2-EVO before 22.2R3-S4-EVO;
• from 22.3-EVO before 22.3R3-S3-EVO;
• from 22.4-EVO before 22.4R3-EVO;
• from 23.2-EVO before 23.2R2-EVO.
• from 23.4-EVO before 23.4R1-S1-EVO.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-21590
• https://supportportal.juniper.net/JSA75728
• https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N