# CVE-2019-1851: Cisco Identity Services Engine Arbitrary Client Certificate Creation Vulnerability

> Authenticated attackers can exploit RBAC flaws in the ERS API to generate trusted certificates, enabling unauthorized access to protected networks.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 May 2019
- **Updated:** 21 Nov 2024
- **Also known as:** GHSA-6wxc-vxm7-4wrp

## What is CVE-2019-1851?

CVE-2019-1851 is a medium-severity missing authorization vulnerability in Cisco Identity Services Engine, published on 16 May 2019. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability in the External RESTful Services (ERS) API of the Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to generate arbitrary certificates signed by the Internal Certificate Authority (CA) Services on ISE. This vulnerability is due to an incorrect implementation of role-based access control (RBAC). An attacker could exploit this vulnerability by crafting a specific HTTP request with administrative credentials. A successful exploit could allow the attacker to generate a certificate that is signed and trusted by the ISE CA with arbitrary attributes. The attacker could use this certificate to access other networks or assets that are protected by certificate authentication.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2019-1851?

It affects 1 product.


Products: Cisco Identity Services Engine.

## How do I fix CVE-2019-1851?

No fix has been published for CVE-2019-1851 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1851 being exploited?

There is no known exploitation of CVE-2019-1851 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Identity Services Engine

- [CVE-2026-76460](https://insights.sbomify.com/CVE-2026-76460/): Cisco Identity Services Engine Incorrect Use of Privileged APIs (critical 10.0, exploited in the wild)
- [CVE-2025-20337](https://insights.sbomify.com/CVE-2025-20337/): Cisco Identity Services Engine Injection (critical 10.0, exploited in the wild)
- [CVE-2025-20281](https://insights.sbomify.com/CVE-2025-20281/): Cisco Identity Services Engine Injection (critical 10.0, exploited in the wild)
- [CVE-2026-20130](https://insights.sbomify.com/CVE-2026-20130/): Cisco Identity Services Engine Hardening Release - Improper Neutralization Vulnerabilities (critical 10.0)
- [CVE-2026-20192](https://insights.sbomify.com/CVE-2026-20192/): Cisco Identity Services Engine Hardening Release - Access Control Vulnerabilities (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1851 and fix it if it is affected.

What it is: CVE-2019-1851 is a medium-severity missing authorization vulnerability in Cisco Identity Services Engine, published on 16 May 2019. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-1851 in the wild and no public exploit code.

Affected product: Cisco Identity Services Engine. 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-2019-1851/ (Markdown: https://insights.sbomify.com/CVE-2019-1851/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1851
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1851
- OSV: https://osv.dev/vulnerability/CVE-2019-1851

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-1851/
Summaries are generated and may contain mistakes; the official description above is the record.