# CVE-2021-1388: Cisco ACI Multi-Site Orchestrator Application Services Engine Deployment Authentication Bypass Vulnerability

> Unauthenticated remote attackers can bypass authentication to obtain administrator-level tokens for Cisco ACI Multi-Site Orchestrator and managed APIC devices.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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:** 24 Feb 2021
- **Updated:** 8 Nov 2024
- **Also known as:** GHSA-m8g7-f94v-5fp8

## What is CVE-2021-1388?

CVE-2021-1388 is a critical authentication bypass vulnerability in Cisco ACI Multi-Site Orchestrator Software, published on 24 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in an API endpoint of Cisco ACI Multi-Site Orchestrator (MSO) installed on the Application Services Engine could allow an unauthenticated, remote attacker to bypass authentication on an affected device. The vulnerability is due to improper token validation on a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted request to the affected API. A successful exploit could allow the attacker to receive a token with administrator-level privileges that could be used to authenticate to the API on affected MSO and managed Cisco Application Policy Infrastructure Controller (APIC) devices.

Weakness: CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2021-1388?

It affects 2 products.


Products: Cisco Aci Multi-Site Orchestrator, Cisco Application Policy Infrastructure Controller.

## How do I fix CVE-2021-1388?

No fix has been published for CVE-2021-1388 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1388 being exploited?

There is no known exploitation of CVE-2021-1388 in the wild and no public exploit code.

## Other vulnerabilities in Cisco ACI Multi-Site Orchestrator Software

- [CVE-2022-20921](https://insights.sbomify.com/CVE-2022-20921/): Cisco ACI Multi-Site Orchestrator Privilege Escalation Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1388 and fix it if it is affected.

What it is: CVE-2021-1388 is a critical authentication bypass vulnerability in Cisco ACI Multi-Site Orchestrator Software, published on 24 Feb 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-2021-1388 in the wild and no public exploit code.

Affected product: Cisco ACI Multi-Site Orchestrator Software. 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-2021-1388/ (Markdown: https://insights.sbomify.com/CVE-2021-1388/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1388
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1388
- OSV: https://osv.dev/vulnerability/CVE-2021-1388

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1388/
Summaries are generated and may contain mistakes; the official description above is the record.