# CVE-2021-0282: Junos OS: RPD crash while processing a specific BGP UPDATE when Multipath or add-path features are enabled

> Attackers can crash the routing process daemon on Juniper devices with Multipath or add-path enabled, causing a sustained denial of service.

- **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:** 15 Jul 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-26fj-m6r6-qg3j

## What is CVE-2021-0282?

CVE-2021-0282 is a high-severity denial of service vulnerability in Juniper Junos, published on 15 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

On Juniper Networks Junos OS devices with Multipath or add-path feature enabled, processing a specific BGP UPDATE can lead to a routing process daemon (RPD) crash and restart, causing a Denial of Service (DoS). Continued receipt and processing of this UPDATE message will create a sustained Denial of Service (DoS) condition. This BGP UPDATE message can propagate to other BGP peers with vulnerable Junos versions on which Multipath or add-path feature is enabled, and cause RPD to crash and restart. This issue affects both IBGP and EBGP deployments in IPv4 or IPv6 network. Junos OS devices that do not have the BGP Multipath or add-path feature enabled are not affected by this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S18; 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R2-S6, 18.4R3-S6; 19.1 versions prior to 19.1R3-S3;

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2021-0282?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2021-0282?

No fix has been published for CVE-2021-0282 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-0282 being exploited?

There is no known exploitation of CVE-2021-0282 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-2021-0282 and fix it if it is affected.

What it is: CVE-2021-0282 is a high-severity denial of service vulnerability in Juniper Junos, published on 15 Jul 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-2021-0282 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-2021-0282/ (Markdown: https://insights.sbomify.com/CVE-2021-0282/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0282
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0282
- OSV: https://osv.dev/vulnerability/CVE-2021-0282

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0282/
Summaries are generated and may contain mistakes; the official description above is the record.