# CVE-2024-30386: Use after free in Junos OS

> An unauthenticated adjacent attacker can cause a denial of service in Junos OS by triggering a use-after-free crash in the l2ald process during EVPN-VXLAN state updates.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Apr 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-r4g7-rp4j-9cv7

## What is CVE-2024-30386?

CVE-2024-30386 is a high-severity use after free vulnerability in Juniper Junos, published on 12 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A Use-After-Free vulnerability in the Layer 2 Address Learning Daemon (l2ald)

 of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause l2ald to crash leading to a Denial-of-Service (DoS).

In an EVPN-VXLAN scenario, when 

state updates are received and processed by the affected system, the correct order of some processing steps is not ensured, which can lead to an l2ald crash and restart. Whether the crash occurs depends on system internal timing which is outside the attackers control.
This issue affects:

Junos OS: 

  *  All versions before 20.4R3-S8,
  *  21.2 versions before 21.2R3-S6,
  *  21.3 versions before 21.3R3-S5,
  *  21.4 versions before 21.4R3-S4,
  *  22.1 versions before 22.1R3-S3,
  *  22.2 versions before 22.2R3-S1,
  *  22.3 versions before 22.3R3,,
  *  22.4 versions before 22.4R2;

Junos OS Evolved: 

  *  All versions before 20.4R3-S8-EVO,
  *  21.2-EVO versions before 21.2R3-S6-EVO, 
  *  21.3-EVO

 versions before 21.3R3-S5-EVO,
  *  21.4-EVO

 versions before 21.4R3-S4-EVO,
  *  22.1-EVO

 versions before 22.1R3-S3-EVO,
  *  22.2-EVO

 versions before 22.2R3-S1-EVO,
  *  22.3-EVO

 versions before 22.3R3-EVO,
  *  22.4-EVO

 versions before 22.4R2-EVO.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-30386?

It affects 2 products.


Products: Juniper Junos, Juniper Junos Os Evolved.

## How do I fix CVE-2024-30386?

No fix has been published for CVE-2024-30386 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-30386 being exploited?

There is no known exploitation of CVE-2024-30386 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-2024-30386 and fix it if it is affected.

What it is: CVE-2024-30386 is a high-severity use after free vulnerability in Juniper Junos, published on 12 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-30386 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-2024-30386/ (Markdown: https://insights.sbomify.com/CVE-2024-30386/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-30386
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-30386
- OSV: https://osv.dev/vulnerability/CVE-2024-30386

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-30386/
Summaries are generated and may contain mistakes; the official description above is the record.