# CVE-2024-53695: HBS 3 Hybrid Backup Sync

> Remote attackers can exploit a buffer overflow in QNAP HBS 3 to modify memory, execute code, or crash processes.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Mar 2025
- **Updated:** 7 Mar 2025
- **Also known as:** GHSA-56j5-vwwf-v97g

## What is CVE-2024-53695?

CVE-2024-53695 is a medium-severity memory corruption vulnerability in QNAP Systems Inc. HBS 3 Hybrid Backup Sync, published on 7 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A buffer overflow vulnerability has been reported to affect HBS 3 Hybrid Backup Sync. If exploited, the vulnerability could allow remote attackers to modify memory or crash processes.

We have already fixed the vulnerability in the following version:
HBS 3 Hybrid Backup Sync 25.1.4.952 and later

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2024-53695?

It affects 1 product.


Products: Qnap Hybrid Backup Sync.

## How do I fix CVE-2024-53695?

No fix has been published for CVE-2024-53695 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-53695 being exploited?

There is no known exploitation of CVE-2024-53695 in the wild and no public exploit code.

## Other vulnerabilities in QNAP Systems Inc. HBS 3 Hybrid Backup Sync

- [CVE-2021-28799](https://insights.sbomify.com/CVE-2021-28799/): QNAP NAS Improper Authorization (critical 10.0, exploited in the wild)
- [CVE-2021-28809](https://insights.sbomify.com/CVE-2021-28809/): Missing Authentication for Critical Function in RTRR Server in HBS3 (critical 9.8)
- [CVE-2024-50388](https://insights.sbomify.com/CVE-2024-50388/): HBS 3 Hybrid Backup Sync (critical 9.5)
- [CVE-2025-62840](https://insights.sbomify.com/CVE-2025-62840/): HBS 3 Hybrid Backup Sync (high 7.0)
- [CVE-2025-62842](https://insights.sbomify.com/CVE-2025-62842/): HBS 3 Hybrid Backup Sync (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-53695 and fix it if it is affected.

What it is: CVE-2024-53695 is a medium-severity memory corruption vulnerability in QNAP Systems Inc. HBS 3 Hybrid Backup Sync, published on 7 Mar 2025. 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-2024-53695 in the wild and no public exploit code.

Affected product: QNAP Systems Inc. HBS 3 Hybrid Backup Sync. 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-2024-53695/ (Markdown: https://insights.sbomify.com/CVE-2024-53695/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-53695
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-53695
- OSV: https://osv.dev/vulnerability/CVE-2024-53695

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-53695/
Summaries are generated and may contain mistakes; the official description above is the record.