# CVE-2023-22408: Junos OS: SRX 5000 Series: Upon processing of a specific SIP packet an FPC can crash

> An unauthenticated attacker can cause a sustained denial of service on Juniper SRX 5000 Series devices by sending malformed SIP packets when specific SIP ALG features are enabled.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 12 Jan 2023
- **Updated:** 7 Apr 2025
- **Also known as:** GHSA-4w9j-m79h-8w8m

## What is CVE-2023-22408?

CVE-2023-22408 is a high-severity denial of service vulnerability in Juniper Junos, published on 12 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Improper Validation of Array Index vulnerability in the SIP ALG of Juniper Networks Junos OS on SRX 5000 Series allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). When an attacker sends an SIP packets with a malformed SDP field then the SIP ALG can not process it which will lead to an FPC crash and restart. Continued receipt of these specific packets will lead to a sustained Denial of Service. This issue can only occur when both below mentioned conditions are fulfilled: 1. Call distribution needs to be enabled: [security alg sip enable-call-distribution] 2. The SIP ALG needs to be enabled, either implicitly / by default or by way of configuration. To confirm whether SIP ALG is enabled on SRX, and MX with SPC3 use the following command: user@host> show security alg status | match sip SIP : Enabled This issue affects Juniper Networks Junos OS on SRX 5000 Series: 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S3; 21.4 versions prior to 21.4R3-S2; 22.1 versions prior to 22.1R2-S2, 22.1R3; 22.2 versions prior to 22.2R3; 22.3 versions prior to 22.3R1-S1, 22.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1.

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2023-22408?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2023-22408?

No fix has been published for CVE-2023-22408 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-22408 being exploited?

There is no known exploitation of CVE-2023-22408 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-2023-22408 and fix it if it is affected.

What it is: CVE-2023-22408 is a high-severity denial of service vulnerability in Juniper Junos, published on 12 Jan 2023. 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-2023-22408 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-2023-22408/ (Markdown: https://insights.sbomify.com/CVE-2023-22408/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-22408
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-22408
- OSV: https://osv.dev/vulnerability/CVE-2023-22408

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-22408/
Summaries are generated and may contain mistakes; the official description above is the record.