# CVE-2021-1393: Cisco Application Services Engine Unauthorized Access Vulnerabilities

> Unauthenticated remote attackers can gain privileged host access, view device information, and modify configurations on Cisco Application Services Engine.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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-m5h3-jr9w-ww4r

## What is CVE-2021-1393?

CVE-2021-1393 is a critical authentication bypass vulnerability in Cisco Application Services Engine 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

Multiple vulnerabilities in Cisco Application Services Engine could allow an unauthenticated, remote attacker to gain privileged access to host-level operations or to learn device-specific information, create diagnostic files, and make limited configuration changes. For more information about these vulnerabilities, see the Details section of this advisory.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2021-1393?

It affects 2 products.


Products: Cisco Application Policy Infrastructure Controller, Cisco Application Services Engine.

## How do I fix CVE-2021-1393?

No fix has been published for CVE-2021-1393 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1393 being exploited?

There is no known exploitation of CVE-2021-1393 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Application Services Engine Software

- [CVE-2021-1396](https://insights.sbomify.com/CVE-2021-1396/): Cisco Application Services Engine Unauthorized Access Vulnerabilities (critical 9.8)
- [CVE-2021-1577](https://insights.sbomify.com/CVE-2021-1577/): Cisco Application Policy Infrastructure Controller Arbitrary File Read and Write Vulnerability (critical 9.1)
- [CVE-2023-20011](https://insights.sbomify.com/CVE-2023-20011/): Cross-site request forgery in Cisco Application Policy Infrastructure Controller (APIC) (high 8.8)
- [CVE-2021-1578](https://insights.sbomify.com/CVE-2021-1578/): Cisco Application Policy Infrastructure Controller Privilege Escalation Vulnerability (high 8.8)
- [CVE-2021-1579](https://insights.sbomify.com/CVE-2021-1579/): Cisco Application Policy Infrastructure Controller App Privilege Escalation Vulnerability (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1393 and fix it if it is affected.

What it is: CVE-2021-1393 is a critical authentication bypass vulnerability in Cisco Application Services Engine 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-2021-1393 in the wild and no public exploit code.

Affected product: Cisco Application Services Engine 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-2021-1393/ (Markdown: https://insights.sbomify.com/CVE-2021-1393/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1393
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1393
- OSV: https://osv.dev/vulnerability/CVE-2021-1393

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1393/
Summaries are generated and may contain mistakes; the official description above is the record.