HOMEVULNERABILITIESCVE-2021-22876
MEDIUM

CVE-2021-22876

CWE-359Published: April 1, 2021· Updated: Jun 17, 2026

5.3
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-22876 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected Vendors & Products

broadcom1 product(s)
fabric operating system
Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
haxx1 product(s)
libcurl
netapp4 product(s)
hci management nodesolidfirehci compute nodehci storage node
Oracle2 product(s)
communications billing and revenue managementessbase
siemens1 product(s)
sinec infrastructure network services
splunk1 product(s)
universal forwarder
Source: NVD CPE · 15 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
PATCHhttps://curl.se/docs/CVE-2021-22876.html
PATCHhttps://hackerone.com/reports/1101882
PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
PATCHhttps://curl.se/docs/CVE-2021-22876.html
PATCHhttps://hackerone.com/reports/1101882
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/05/msg00019.html
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/
ADVISORYhttps://security.gentoo.org/glsa/202105-36
ADVISORYhttps://security.netapp.com/advisory/ntap-20210521-0007/
ADVISORYhttps://www.oracle.com//security-alerts/cpujul2021.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/05/msg00019.html
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/
ADVISORYhttps://security.gentoo.org/glsa/202105-36
ADVISORYhttps://security.netapp.com/advisory/ntap-20210521-0007/
ADVISORYhttps://www.oracle.com//security-alerts/cpujul2021.html

All References (20)

→
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch · Third Party Advisory
→
https://curl.se/docs/CVE-2021-22876.htmlPatch · Vendor Advisory
→
https://hackerone.com/reports/1101882Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/05/msg00019.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/Mailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/Mailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/Mailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202105-36Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20210521-0007/Third Party Advisory
→
https://www.oracle.com//security-alerts/cpujul2021.htmlThird Party Advisory
→
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch · Third Party Advisory
→
https://curl.se/docs/CVE-2021-22876.htmlPatch · Vendor Advisory
→
https://hackerone.com/reports/1101882Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/05/msg00019.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/Mailing List · Third Party Advisory

Quick Facts

CVE IDCVE-2021-22876
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-359
CISA KEVNo
Affected8 vendor(s)
PublishedApr 1, 2021

Related CVEs (CWE-359)

CVE-2023-36018
9.8
CVE-2025-15623
9.3
CVE-2024-49765
9.1
CVE-2022-2921
8.8
CVE-2025-53625
8.7
CVE-2023-36052
8.6

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-22876 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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