High · published April 9, 2025
An Improper Input Validation vulnerability in the syslog stream TCP transport of Juniper Networks Junos OS on MX240, MX480 and MX960 devices with MX-SPC3 Security Services Card allows an unauthenticated, network-based attacker, to send specific spoofed packets to cause a CPU Denial of Service (DoS) to the MX-SPC3 SPUs.
Continued receipt and processing of these specific packets will sustain the DoS condition.
This issue affects Junos OS: * All versions before 22.2R3-S6,
* from 22.4 before 22.4R3-S4,
* from 23.2 before 23.2R2-S3,
* from 23.4 before 23.4R2-S4,
* from 24.2 before 24.2R1-S2, 24.2R2
An indicator of compromise will indicate the SPC3 SPUs utilization has spiked.
For example:
user@device> show services service-sets summary
Service sets CPU
Interface configured Bytes used Session bytes used Policy bytes used utilization
"interface" 1 "bytes" (percent%) "sessions" ("percent"%) "bytes" ("percent"%) 99.97 % OVLD <<<<<< look for high CPU usage