# CVE-2024-30410: Junos OS: EX4300 Series: Loopback filter not blocking traffic despite having discard term.

> Attackers can bypass IPv6 loopback firewall filters on Juniper EX4300 switches, allowing traffic to reach the routing engine despite discard rules.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Apr 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-96r2-52xr-8x9x

## What is CVE-2024-30410?

CVE-2024-30410 is a medium-severity vulnerability in Juniper Junos, published on 12 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Incorrect Behavior Order in the routing engine (RE) of Juniper Networks Junos OS on EX4300 Series allows traffic intended to the device to reach the RE instead of being discarded when the discard term is set in loopback (lo0) interface. The intended function is that the lo0 firewall filter takes precedence over the revenue interface firewall filter. 

This issue affects only IPv6 firewall filter.

This issue only affects the EX4300 switch.  No other products or platforms are affected by this vulnerability. 

This issue affects Juniper Networks Junos OS:

  *  All versions before 20.4R3-S10,
  *  from 21.2 before 21.2R3-S7,
  *  from 21.4 before 21.4R3-S6.

Weakness: CWE-696 (Incorrect Behavior Order)

## Which versions are affected by CVE-2024-30410?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2024-30410?

No fix has been published for CVE-2024-30410 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-30410 being exploited?

There is no known exploitation of CVE-2024-30410 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos

- [CVE-2023-36845](https://insights.sbomify.com/CVE-2023-36845/): Juniper Junos OS EX Series and SRX Series PHP External Variable Modification (critical 9.8, exploited in the wild)
- [CVE-2020-1631](https://insights.sbomify.com/CVE-2020-1631/): Juniper Junos OS Path Traversal (high 8.8, exploited in the wild)
- [CVE-2025-21590](https://insights.sbomify.com/CVE-2025-21590/): Juniper Junos OS Improper Isolation or Compartmentalization (medium 6.7, exploited in the wild)
- [CVE-2023-36851](https://insights.sbomify.com/CVE-2023-36851/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, exploited in the wild)
- [CVE-2023-36844](https://insights.sbomify.com/CVE-2023-36844/): Juniper Junos OS EX Series PHP External Variable Modification (medium 5.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-30410 and fix it if it is affected.

What it is: CVE-2024-30410 is a medium-severity vulnerability in Juniper Junos, published on 12 Apr 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-2024-30410 in the wild and no public exploit code.

Affected product: Juniper Junos. 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-2024-30410/ (Markdown: https://insights.sbomify.com/CVE-2024-30410/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-30410
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-30410
- OSV: https://osv.dev/vulnerability/CVE-2024-30410

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-30410/
Summaries are generated and may contain mistakes; the official description above is the record.