---
id: CVE-2022-43552
title: A use after free vulnerability exists in curl <7.87.0
summary: >-
  A use after free vulnerability exists in curl <7.87.0. Curl can be asked to
  *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP
  proxies can (and often do) deny such tunnel operations. When getting denied to
  tunnel th…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-416
  - CWE-416
  - CWE-416
vendor: haxx
product: curl
affected:
  - curl < 7.87.0
  - 'macos >= 13.0, < 13.3'
  - '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
  - macos 13.3
  - universal_forwarder 9.0.6
published: '2023-02-09'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T19:16:53.430'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-43552'
references:
  - url: 'http://seclists.org/fulldisclosure/2023/Mar/17'
    label: support@hackerone.com
  - url: 'https://hackerone.com/reports/1764858'
    label: support@hackerone.com
  - url: 'https://security.gentoo.org/glsa/202310-12'
    label: support@hackerone.com
  - url: 'https://security.netapp.com/advisory/ntap-20230214-0002/'
    label: support@hackerone.com
  - url: 'https://support.apple.com/kb/HT213670'
    label: support@hackerone.com
  - url: 'http://seclists.org/fulldisclosure/2023/Mar/17'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://hackerone.com/reports/1764858'
    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-20230214-0002/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://support.apple.com/kb/HT213670'
    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: 0.02511
epssPercentile: 0.84462
ingestedAt: '2026-10-14T19:49:57.530Z'
---

## Overview

A use after free vulnerability exists in curl <7.87.0. Curl can be asked to *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.

## Affected

- `curl < 7.87.0`
- `macos >= 13.0, < 13.3`
- `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`
- `macos 13.3`
- `universal_forwarder 9.0.6`