# CVE-2021-0260: Junos OS: SNMP fails to properly perform authorization checks on incoming received SNMP requests.

> Unauthenticated attackers can perform SNMP read and write actions on Juniper Junos OS devices due to improper authorization checks in the snmpd service.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-pcw8-h376-q646

## What is CVE-2021-0260?

CVE-2021-0260 is a high-severity missing authorization vulnerability in Juniper Junos, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An improper authorization vulnerability in the Simple Network Management Protocol daemon (snmpd) service of Juniper Networks Junos OS leads an unauthenticated attacker being able to perform SNMP read actions, an Exposure of System Data to an Unauthorized Control Sphere, or write actions to OIDs that support write operations, against the device without authentication. This issue affects: Juniper Networks Junos OS: 17.2 version 17.2R1 and later versions; 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S12, 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R2-S5, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S6, 19.2R2; 19.3 versions prior to 19.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1.

Weakness: CWE-497 (Exposure of Sensitive System Information to an Unauthorized Control Sphere), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2021-0260?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2021-0260?

No fix has been published for CVE-2021-0260 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-0260 being exploited?

There is no known exploitation of CVE-2021-0260 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-2021-0260 and fix it if it is affected.

What it is: CVE-2021-0260 is a high-severity missing authorization vulnerability in Juniper Junos, published on 22 Apr 2021. 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-2021-0260 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-2021-0260/ (Markdown: https://insights.sbomify.com/CVE-2021-0260/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0260
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0260
- OSV: https://osv.dev/vulnerability/CVE-2021-0260

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0260/
Summaries are generated and may contain mistakes; the official description above is the record.