# CVE-2021-3622: Denial of service in hivex

> An attacker can cause a stack overflow and denial of service in the hivex library by providing a specially crafted Windows Registry hive file.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L`)
- **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:** Yes
- **Published:** 23 Dec 2021
- **Updated:** 3 Aug 2024
- **Also known as:** AZL-7096, CLSA-2025-1738170241, CLSA-2025-1738170437, DEBIAN-CVE-2021-3622, GHSA-rc2r-2mcx-6h65, MGASA-2021-0528, OESA-2021-1361, RHSA-2021:3338, SUSE-SU-2021:3201-1, SUSE-SU-2021:3201-2, SUSE-SU-2021:3210-1, UBUNTU-CVE-2021-3622, openSUSE-SU-2021:1319-1, openSUSE-SU-2021:3201-1

## What is CVE-2021-3622?

CVE-2021-3622 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 23 Dec 2021. 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 flaw was found in the hivex library. This flaw allows an attacker to input a specially crafted Windows Registry (hive) file, which would cause hivex to recursively call the _get_children() function, leading to a stack overflow. The highest threat from this vulnerability is to system availability.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2021-3622?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `hivex` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `perl-hivex` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `python-hivex` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `ruby-hivex` | Red Hat:enterprise_linux:7::client | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `perl-hivex` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `python-hivex` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `ruby-hivex` | Red Hat:enterprise_linux:7::server | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `ocaml-hivex-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `perl-hivex` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `python-hivex` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `ruby-hivex` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.3.10-6.12.el7_9 |
| `hivex` | SUSE:Linux Enterprise Micro 5.0 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Micro 5.1 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Module for Basesystem 15 SP3 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Module for Development Tools 15 SP2 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Module for Development Tools 15 SP3 | All versions | 1.3.14-5.6.1 |
| `hivex` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.3.10-5.7.1 |
| `hivex` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.3.10-5.7.1 |
| `hivex` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.3.10-5.7.1 |
| `hivex` | openSUSE:Leap 15.2 | All versions | 1.3.14-lp152.4.6.1 |
| `hivex` | openSUSE:Leap 15.3 | All versions | 1.3.14-5.6.1 |

Products: Fedoraproject Fedora, Redhat Enterprise Linux, Redhat Enterprise Linux Workstation, Redhat Hivex.

## How do I fix CVE-2021-3622?

Apply the vendor's patch.

## Is CVE-2021-3622 being exploited?

There is no known exploitation of CVE-2021-3622 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3622 and fix it if it is affected.

What it is: CVE-2021-3622 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 23 Dec 2021. 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-2021-3622 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-3622/ (Markdown: https://insights.sbomify.com/CVE-2021-3622/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3622
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3622
- OSV: https://osv.dev/vulnerability/CVE-2021-3622

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3622/
Summaries are generated and may contain mistakes; the official description above is the record.
