---
id: CVE-2021-22876
title: >-
  curl 7.1.1 to and including 7.75.0 is vulnerable to an "Exposure of Private
  Personal Information to an Unauthorized Actor" by leaking credentials in the
  HTTP Referer: header
summary: >-
  curl 7.1.1 to and including 7.75.0 is vulnerable to an "Exposure of Private
  Personal Information to an Unauthorized Actor" by leaking credentials in the
  HTTP Referer: header. libcurl does not strip off user credentials from the URL
  when …
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-359
  - CWE-200
vendor: haxx
product: libcurl
affected:
  - 'libcurl >= 7.1.1, <= 7.75.0'
  - fedora = 32
  - fedora = 33
  - fedora = 34
  - hci_management_node
  - solidfire
  - hci_compute_node
  - hci_storage_node
  - fabric_operating_system
  - debian_linux = 9.0
  - sinec_infrastructure_network_services < 1.0.1.1
  - communications_billing_and_revenue_management = 12.0.0.3.0
  - essbase = 21.2
  - 'universal_forwarder >= 8.2.0, < 8.2.12'
  - 'universal_forwarder >= 9.0.0, < 9.0.6'
  - universal_forwarder = 9.1.0
patched:
  - sinec_infrastructure_network_services 1.0.1.1
  - universal_forwarder 9.0.6
published: '2021-04-01'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T11:16:52.113'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-22876'
references:
  - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf'
    label: support@hackerone.com
  - url: 'https://curl.se/docs/CVE-2021-22876.html'
    label: support@hackerone.com
  - url: 'https://hackerone.com/reports/1101882'
    label: support@hackerone.com
  - url: 'https://lists.debian.org/debian-lts-announce/2021/05/msg00019.html'
    label: support@hackerone.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/
    label: support@hackerone.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/
    label: support@hackerone.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/
    label: support@hackerone.com
  - url: 'https://security.gentoo.org/glsa/202105-36'
    label: support@hackerone.com
  - url: 'https://security.netapp.com/advisory/ntap-20210521-0007/'
    label: support@hackerone.com
  - url: 'https://www.oracle.com//security-alerts/cpujul2021.html'
    label: support@hackerone.com
  - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://curl.se/docs/CVE-2021-22876.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://hackerone.com/reports/1101882'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2021/05/msg00019.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202105-36'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210521-0007/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com//security-alerts/cpujul2021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-389290.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.05301
epssPercentile: 0.92417
ingestedAt: '2026-10-14T11:27:22.122Z'
---

## Overview

curl 7.1.1 to and including 7.75.0 is vulnerable to an "Exposure of Private Personal Information to an Unauthorized Actor" by leaking credentials in the HTTP Referer: header. libcurl does not strip off user credentials from the URL when automatically populating the Referer: HTTP request header field in outgoing HTTP requests, and therefore risks leaking sensitive data to the server that is the target of the second HTTP request.

## Affected

- `libcurl >= 7.1.1, <= 7.75.0`
- `fedora = 32`
- `fedora = 33`
- `fedora = 34`
- `hci_management_node`
- `solidfire`
- `hci_compute_node`
- `hci_storage_node`
- `fabric_operating_system`
- `debian_linux = 9.0`
- `sinec_infrastructure_network_services < 1.0.1.1`
- `communications_billing_and_revenue_management = 12.0.0.3.0`
- `essbase = 21.2`
- `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:

- `sinec_infrastructure_network_services 1.0.1.1`
- `universal_forwarder 9.0.6`