# CVE-2021-34731: Cisco Prime Access Registrar Stored Cross-Site Scripting Vulnerability

> Authenticated attackers can inject malicious scripts into the web interface, enabling arbitrary code execution or data theft in victim browsers.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 4 Nov 2021
- **Updated:** 7 Nov 2024
- **Also known as:** GHSA-g8rc-p2f3-v3x7

## What is CVE-2021-34731?

CVE-2021-34731 is a medium-severity cross-site scripting vulnerability in Cisco Prime Access Registrar, published on 4 Nov 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

A vulnerability in the web-based management interface of Cisco Prime Access Registrar could allow an authenticated, remote attacker to perform a stored cross-site scripting attack on an affected system. This vulnerability exists because the web-based management interface does not sufficiently validate user-supplied input. An attacker could exploit this vulnerability by injecting malicious code into specific pages of the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. To exploit this vulnerability, the attacker would need valid administrative credentials. Cisco expects to release software updates that address this vulnerability.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-34731?

It affects 1 product.


Products: Cisco Prime Access Registrar.

## How do I fix CVE-2021-34731?

No fix has been published for CVE-2021-34731 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34731 being exploited?

There is no known exploitation of CVE-2021-34731 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Prime Access Registrar

- [CVE-2018-0421](https://insights.sbomify.com/CVE-2018-0421/): Cisco Prime Access Registrar Denial of Service Vulnerability (high 8.6)
- [CVE-2022-20626](https://insights.sbomify.com/CVE-2022-20626/): Cisco Prime Access Registrar Appliance Cross-Site Scripting Vulnerability (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34731 and fix it if it is affected.

What it is: CVE-2021-34731 is a medium-severity cross-site scripting vulnerability in Cisco Prime Access Registrar, published on 4 Nov 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-34731 in the wild and no public exploit code.

Affected product: Cisco Prime Access Registrar. 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-2021-34731/ (Markdown: https://insights.sbomify.com/CVE-2021-34731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34731
- OSV: https://osv.dev/vulnerability/CVE-2021-34731

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-34731/
Summaries are generated and may contain mistakes; the official description above is the record.