# CVE-2022-22167: Junos OS: SRX Series: If no-syn-check is enabled, traffic classified as UNKNOWN gets permitted by pre-id-default-policy

> Attackers can bypass Deep Packet Inspection rules and access unauthorized networks on Juniper SRX devices if no-syn-check is enabled.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Jan 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-p6cr-hm6f-97rw

## What is CVE-2022-22167?

CVE-2022-22167 is a high-severity vulnerability in Juniper Junos, published on 19 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A traffic classification vulnerability in Juniper Networks Junos OS on the SRX Series Services Gateways may allow an attacker to bypass Juniper Deep Packet Inspection (JDPI) rules and access unauthorized networks or resources, when 'no-syn-check' is enabled on the device. While JDPI correctly classifies out-of-state asymmetric TCP flows as the dynamic-application UNKNOWN, this classification is not provided to the policy module properly and hence traffic continues to use the pre-id-default-policy, which is more permissive, causing the firewall to allow traffic to be forwarded that should have been denied. This issue only occurs when 'set security flow tcp-session no-syn-check' is configured on the device. This issue affects Juniper Networks Junos OS on SRX Series: 18.4 versions prior to 18.4R2-S10, 18.4R3-S10; 19.1 versions prior to 19.1R3-S8; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.3 versions prior to 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2-S2, 21.1R3; 21.2 versions prior to 21.2R2. This issue does not affect Juniper Networks Junos OS versions prior to 18.4R1.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2022-22167?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2022-22167?

No fix has been published for CVE-2022-22167 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-22167 being exploited?

There is no known exploitation of CVE-2022-22167 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-2022-22167 and fix it if it is affected.

What it is: CVE-2022-22167 is a high-severity vulnerability in Juniper Junos, published on 19 Jan 2022. 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-2022-22167 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-2022-22167/ (Markdown: https://insights.sbomify.com/CVE-2022-22167/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-22167
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-22167
- OSV: https://osv.dev/vulnerability/CVE-2022-22167

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-22167/
Summaries are generated and may contain mistakes; the official description above is the record.