# CVE-2018-15919: Information disclosure in n/a

> Remote attackers can enumerate valid usernames on OpenSSH servers when GSS2 authentication is enabled, revealing user existence.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2018
- **Updated:** 18 Dec 2025
- **Also known as:** DEBIAN-CVE-2018-15919, GHSA-rj3q-q9f3-gr2v, ROOT-OS-DEBIAN-12-CVE-2018-15919, UBUNTU-CVE-2018-15919

## What is CVE-2018-15919?

CVE-2018-15919 is a medium-severity vulnerability in Netapp Cloud Backup, published on 28 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2018-15919?

It affects 6 products.


Products: Netapp Cloud Backup, Netapp Cn1610 Firmware, Netapp Data Ontap Edge, Netapp Ontap Select Deploy, Netapp Steelstore, OpenSSH.

## How do I fix CVE-2018-15919?

No fix published yet.

## Is CVE-2018-15919 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-15919 exists.

## Other vulnerabilities in Netapp Cloud Backup

- [CVE-2019-19646](https://insights.sbomify.com/CVE-2019-19646/): Null dereference in n/a (critical 9.8)
- [CVE-2019-19317](https://insights.sbomify.com/CVE-2019-19317/): Denial of service in n/a (critical 9.8)
- [CVE-2019-16905](https://insights.sbomify.com/CVE-2019-16905/): Integer overflow in n/a (high 7.8)
- [CVE-2020-25692](https://insights.sbomify.com/CVE-2020-25692/): Null dereference in openldap (high 7.5)
- [CVE-2019-19645](https://insights.sbomify.com/CVE-2019-19645/): Denial of service in n/a (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-15919 and fix it if it is affected.

What it is: CVE-2018-15919 is a medium-severity vulnerability in Netapp Cloud Backup, published on 28 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-15919 exists.

Affected product: Netapp Cloud Backup. 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-2018-15919/ (Markdown: https://insights.sbomify.com/CVE-2018-15919/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-15919
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-15919
- OSV: https://osv.dev/vulnerability/CVE-2018-15919

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-15919/
Summaries are generated and may contain mistakes; the official description above is the record.