# CVE-2024-39547: Junos OS and Junos OS Evolved: cRPD: Receipt of crafted TCP traffic can trigger high CPU utilization

> Unauthenticated attackers can cause high CPU utilization and denial of service in Junos OS by sending crafted TCP traffic to the routing engine.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Oct 2024
- **Updated:** 11 Oct 2024
- **Also known as:** GHSA-37f4-v37x-33qj

## What is CVE-2024-39547?

CVE-2024-39547 is a high-severity denial of service vulnerability in Juniper Networks Junos OS, published on 11 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Improper Handling of Exceptional Conditions vulnerability in the rpd-server of Juniper Networks Junos OS and Junos OS Evolved within cRPD allows an unauthenticated network-based attacker sending crafted TCP traffic to the routing engine (RE) to cause a CPU-based Denial of Service (DoS).

If specially crafted TCP traffic is received by the control plane, or a TCP session terminates unexpectedly, it will cause increased control plane CPU utilization by the rpd-server process.

While not explicitly required, the impact is more severe when RIB sharding is enabled.

Task accounting shows unexpected reads by the RPD Server jobs for shards:

user@junos> show task accounting detail
...
read:RPD Server.0.0.0.0+780.192.168.0.78+48886 TOT:00000003.00379787 MAX:00000000.00080516 RUNS: 233888\
read:RPD Server.0.0.0.0+780.192.168.0.78+49144 TOT:00000004.00007565 MAX:00000000.00080360 RUNS: 233888\
read:RPD Server.0.0.0.0+780.192.168.0.78+49694 TOT:00000003.00600584 MAX:00000000.00080463 RUNS: 233888\
read:RPD Server.0.0.0.0+780.192.168.0.78+50246 TOT:00000004.00346998 MAX:00000000.00080338 RUNS: 233888\

This issue affects:

Junos OS with cRPD: 

  *  All versions before 21.2R3-S8, 
  *  21.4 before 21.4R3-S7, 
  *  22.1 before 22.1R3-S6, 
  *  22.2 before 22.2R3-S4, 
  *  22.3 before 22.3R3-S3, 
  *  22.4 before 22.4R3-S2, 
  *  23.2 before 23.2R2-S2, 
  *  24.2 before 24.2R2; 

Junos OS Evolved with cRPD: 

  *  All versions before 21.4R3-S7-EVO, 
  *  22.2 before 22.2R3-S4-EVO, 
  *  22.3 before 22.3R3-S3-EVO, 
  *  22.4 before 22.4R3-S2-EVO, 
  *  23.2 before 23.2R2-EVO.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2024-39547?

It affects 1 product.


Products: Juniper Junos Containerized Routing Protocol Daemon.

## How do I fix CVE-2024-39547?

No fix has been published for CVE-2024-39547 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-39547 being exploited?

There is no known exploitation of CVE-2024-39547 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-39547 and fix it if it is affected.

What it is: CVE-2024-39547 is a high-severity denial of service vulnerability in Juniper Networks Junos OS, published on 11 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-39547 in the wild and no public exploit code.

Affected product: Juniper Networks Junos OS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-39547/ (Markdown: https://insights.sbomify.com/CVE-2024-39547/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39547
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39547
- OSV: https://osv.dev/vulnerability/CVE-2024-39547

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-39547/
Summaries are generated and may contain mistakes; the official description above is the record.