# CVE-2022-43551: Security feature bypass in https://github.com/curl/curl

> Attackers can bypass HSTS enforcement in curl by using IDN characters, forcing insecure HTTP connections instead of HTTPS.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 23 Dec 2022
- **Updated:** 14 Oct 2026
- **Also known as:** ALPINE-CVE-2022-43551, AZL-12107, AZL-12930, AZL-34616, AZL-38788, CLEANSTART-2026-TP15502, CURL-CVE-2022-43551, DEBIAN-CVE-2022-43551, ECHO-a9d3-947b-06ae, GHSA-25m2-mpq4-29vh, JLSEC-2026-400, ROOT-OS-DEBIAN-11-CVE-2022-43551, UBUNTU-CVE-2022-43551

## What is CVE-2022-43551?

CVE-2022-43551 is a high-severity vulnerability in Fedoraproject Fedora, published on 23 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be bypassed if the host name in the given URL first uses IDN characters that get replaced to ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) `.`. Then in a subsequent request, it does not detect the HSTS state and makes a clear text transfer. Because it would store the info IDN encoded but look for it IDN decoded.

Weakness: CWE-319 (Cleartext Transmission of Sensitive Information)

## Which versions are affected by CVE-2022-43551?

It affects 7 products.


Products: Fedoraproject Fedora, Haxx Curl, Netapp Active Iq Unified Manager, Netapp Oncommand Insight, Netapp Oncommand Workflow Automation, Netapp Snapcenter, Splunk Universal Forwarder.

## How do I fix CVE-2022-43551?

Upgrade to a fixed version.

## Is CVE-2022-43551 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-43551 exists.

## 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-2022-43551 and fix it if it is affected.

What it is: CVE-2022-43551 is a high-severity vulnerability in Fedoraproject Fedora, published on 23 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-43551 exists.

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-2022-43551/ (Markdown: https://insights.sbomify.com/CVE-2022-43551/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-43551
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-43551
- OSV: https://osv.dev/vulnerability/CVE-2022-43551

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-43551/
Summaries are generated and may contain mistakes; the official description above is the record.