# CVE-2017-3879: Denial of service in Cisco Nexus 9000 Series Switches

> Unauthenticated remote attackers can cause login process termination on Cisco Nexus switches via Telnet or SSH, requiring Telnet to be enabled.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 17 Mar 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-88f9-c76f-fhv6

## What is CVE-2017-3879?

CVE-2017-3879 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 17 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A Denial of Service vulnerability in the remote login functionality for Cisco NX-OS Software running on Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause a process used for login to terminate unexpectedly and the login attempt to fail. There is no impact to user traffic flowing through the device. The attacker could use either a Telnet or an SSH client for the remote login attempt. Affected Products: This vulnerability affects Cisco Nexus 9000 Series Switches that are running Cisco NX-OS Software and are configured to allow remote Telnet connections to the device. More Information: CSCuy25824. Known Affected Releases: 7.0(3)I3(1) 8.3(0)CV(0.342) 8.3(0)CV(0.345). Known Fixed Releases: 8.3(0)CV(0.362) 8.0(1) 7.0(3)IED5(0.19) 7.0(3)IED5(0) 7.0(3)I4(1) 7.0(3)I4(0.8) 7.0(3)I2(2e) 7.0(3)F1(1.22) 7.0(3)F1(1) 7.0(3)F1(0.230).

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

## Which versions are affected by CVE-2017-3879?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2017-3879?

No fix has been published for CVE-2017-3879 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-3879 being exploited?

There is no known exploitation of CVE-2017-3879 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Nx-Os

- [CVE-2024-20399](https://insights.sbomify.com/CVE-2024-20399/): Cisco NX-OS Command Injection (medium 6.0, exploited in the wild)
- [CVE-2021-1361](https://insights.sbomify.com/CVE-2021-1361/): Cisco NX-OS Software Unauthenticated Arbitrary File Actions Vulnerability (critical 9.8)
- [CVE-2018-0301](https://insights.sbomify.com/CVE-2018-0301/): Memory corruption in Cisco NX-OS unknown (critical 9.8)
- [CVE-2016-1453](https://insights.sbomify.com/CVE-2016-1453/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1341](https://insights.sbomify.com/CVE-2016-1341/): Hardcoded credentials in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-3879 and fix it if it is affected.

What it is: CVE-2017-3879 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 17 Mar 2017. 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-2017-3879 in the wild and no public exploit code.

Affected product: Cisco Nx-Os. 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-2017-3879/ (Markdown: https://insights.sbomify.com/CVE-2017-3879/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3879
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3879
- OSV: https://osv.dev/vulnerability/CVE-2017-3879

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-3879/
Summaries are generated and may contain mistakes; the official description above is the record.