---
id: CVE-2022-43551
title: >-
  A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to
  trick it to keep using HTTP
summary: >-
  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
  prov…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-319
  - CWE-319
vendor: haxx
product: curl
affected:
  - 'curl >= 7.77.0, < 7.87.0'
  - fedora = 37
  - active_iq_unified_manager
  - oncommand_insight
  - oncommand_workflow_automation
  - snapcenter
  - 'universal_forwarder >= 8.2.0, < 8.2.12'
  - 'universal_forwarder >= 9.0.0, < 9.0.6'
  - universal_forwarder = 9.1.0
patched:
  - curl 7.87.0
  - universal_forwarder 9.0.6
published: '2022-12-23'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T19:16:53.227'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-43551'
references:
  - url: 'https://hackerone.com/reports/1755083'
    label: support@hackerone.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TVWZW5CNSJ7UYAF2BGSYAWAEXDJYUBHA/
    label: support@hackerone.com
  - url: 'https://security.gentoo.org/glsa/202310-12'
    label: support@hackerone.com
  - url: 'https://security.netapp.com/advisory/ntap-20230427-0007/'
    label: support@hackerone.com
  - url: 'https://hackerone.com/reports/1755083'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TVWZW5CNSJ7UYAF2BGSYAWAEXDJYUBHA/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202310-12'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20230427-0007/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-892048.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.1654
epssPercentile: 0.96965
ingestedAt: '2026-10-14T19:49:57.528Z'
---

## Overview

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.

## Affected

- `curl >= 7.77.0, < 7.87.0`
- `fedora = 37`
- `active_iq_unified_manager`
- `oncommand_insight`
- `oncommand_workflow_automation`
- `snapcenter`
- `universal_forwarder >= 8.2.0, < 8.2.12`
- `universal_forwarder >= 9.0.0, < 9.0.6`
- `universal_forwarder = 9.1.0`

## Remediation

Upgrade past the affected range:

- `curl 7.87.0`
- `universal_forwarder 9.0.6`