# CVE-2018-0002: MX series, SRX series: Junos OS: Denial of service vulnerability in Flowd on devices with ALG enabled.

> Attackers can cause a denial of service by crashing the flowd daemon via crafted packets on Juniper devices with ALG enabled.

- **Severity:** High 8.2 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Jan 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-w7r7-44qw-8v64

## What is CVE-2018-0002?

CVE-2018-0002 is a high-severity memory corruption vulnerability in Juniper Junos, published on 10 Jan 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

On SRX Series and MX Series devices with a Service PIC with any ALG enabled, a crafted TCP/IP response packet processed through the device results in memory corruption leading to a flowd daemon crash. Sustained crafted response packets lead to repeated crashes of the flowd daemon which results in an extended Denial of Service condition. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D60 on SRX series; 12.3X48 versions prior to 12.3X48-D35 on SRX series; 14.1 versions prior to 14.1R9 on MX series; 14.2 versions prior to 14.2R8 on MX series; 15.1X49 versions prior to 15.1X49-D60 on SRX series; 15.1 versions prior to 15.1R5-S8, 15.1F6-S9, 15.1R6-S4, 15.1R7 on MX series; 16.1 versions prior to 16.1R6 on MX series; 16.2 versions prior to 16.2R3 on MX series; 17.1 versions prior to 17.1R2-S4, 17.1R3 on MX series. No other Juniper Networks products or platforms are affected by this issue.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2018-0002?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2018-0002?

No fix has been published for CVE-2018-0002 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0002 being exploited?

There is no known exploitation of CVE-2018-0002 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-2018-0002 and fix it if it is affected.

What it is: CVE-2018-0002 is a high-severity memory corruption vulnerability in Juniper Junos, published on 10 Jan 2018. 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-2018-0002 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-2018-0002/ (Markdown: https://insights.sbomify.com/CVE-2018-0002/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0002
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0002
- OSV: https://osv.dev/vulnerability/CVE-2018-0002

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0002/
Summaries are generated and may contain mistakes; the official description above is the record.