# CVE-2021-47960: Information disclosure in Synology SSL VPN Client

> Remote attackers can retrieve sensitive files from the installation directory via a local HTTP server and user interaction, leading to information disclosure.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **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:** 10 Apr 2026
- **Updated:** 10 Apr 2026
- **Also known as:** GHSA-frr3-hpw2-j7cq

## What is CVE-2021-47960?

CVE-2021-47960 is a medium-severity vulnerability in Synology SSL VPN Client, published on 10 Apr 2026. 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

A files or directories accessible to external parties vulnerability in Synology SSL VPN Client before 1.4.5-0684 allows remote attackers to access files within the installation directory via a local HTTP server bound to the loopback interface. By leveraging user interaction with a crafted web page, attackers may retrieve sensitive files such as configuration files, certificates, and logs, leading to information disclosure.

Weakness: CWE-552 (Files or Directories Accessible to External Parties)

## Which versions are affected by CVE-2021-47960?

It affects 1 product.


Products: Synology Ssl Vpn Client.

## How do I fix CVE-2021-47960?

No fix has been published for CVE-2021-47960 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47960 being exploited?

There is no known exploitation of CVE-2021-47960 in the wild and no public exploit code.

## Other vulnerabilities in Synology SSL VPN Client

- [CVE-2018-13283](https://insights.sbomify.com/CVE-2018-13283/): Security feature bypass in SSL VPN Client (high 8.8)
- [CVE-2021-47961](https://insights.sbomify.com/CVE-2021-47961/): Information disclosure in Synology SSL VPN Client (high 8.1)
- [CVE-2018-8929](https://insights.sbomify.com/CVE-2018-8929/): Security feature bypass in SSL VPN Client (high 7.3)
- [CVE-2023-5748](https://insights.sbomify.com/CVE-2023-5748/): Memory corruption in Synology SSL VPN Client (low 3.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47960 and fix it if it is affected.

What it is: CVE-2021-47960 is a medium-severity vulnerability in Synology SSL VPN Client, published on 10 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-47960 in the wild and no public exploit code.

Affected product: Synology SSL VPN Client. 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-2021-47960/ (Markdown: https://insights.sbomify.com/CVE-2021-47960/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47960
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47960
- OSV: https://osv.dev/vulnerability/CVE-2021-47960

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47960/
Summaries are generated and may contain mistakes; the official description above is the record.