# CVE-2023-1720: Bitrix24 Stored Cross-Site Scripting (XSS) via File Upload

> Authenticated attackers can execute arbitrary JavaScript or PHP code by uploading crafted HTML files due to missing MIME type headers.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Nov 2023
- **Updated:** 5 Sep 2024
- **Also known as:** GHSA-3f75-53r3-6ghw

## What is CVE-2023-1720?

CVE-2023-1720 is a critical cross-site scripting vulnerability in Bitrix24, published on 1 Nov 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Lack of mime type response header in Bitrix24 22.0.300 allows authenticated remote attackers to execute arbitrary JavaScript code in the victim's browser, and possibly execute arbitrary PHP code on the server if the victim has administrator privilege, via uploading a crafted HTML file through /desktop_app/file.ajax.php?action=uploadfile.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2023-1720?

It affects 1 product.


Products: Bitrix24 Bitrix24.

## How do I fix CVE-2023-1720?

No fix has been published for CVE-2023-1720 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-1720 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-1720 exists.

## Other vulnerabilities in Bitrix24

- [CVE-2022-27228](https://insights.sbomify.com/CVE-2022-27228/): Code injection in n/a (critical 9.8)
- [CVE-2020-13484](https://insights.sbomify.com/CVE-2020-13484/): Server-side request forgery in n/a (critical 9.8)
- [CVE-2023-1717](https://insights.sbomify.com/CVE-2023-1717/): Bitrix24 Cross-Site Scripting (XSS) via Client-side Prototype Pollution (critical 9.6)
- [CVE-2023-1715](https://insights.sbomify.com/CVE-2023-1715/): Bitrix24 Stored Cross-Site Scripting (XSS) via Improper Input Neutralization on Invoice Edit Page (1 of 2) (critical 9.0)
- [CVE-2023-1716](https://insights.sbomify.com/CVE-2023-1716/): Bitrix24 Stored Cross-Site Scripting (XSS) via Improper Input Neutralization on Invoice Edit Page (2 of 2) (critical 9.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-1720 and fix it if it is affected.

What it is: CVE-2023-1720 is a critical cross-site scripting vulnerability in Bitrix24, published on 1 Nov 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-1720 exists.

Affected product: Bitrix24. 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-2023-1720/ (Markdown: https://insights.sbomify.com/CVE-2023-1720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-1720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-1720
- OSV: https://osv.dev/vulnerability/CVE-2023-1720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-1720/
Summaries are generated and may contain mistakes; the official description above is the record.