Description
This flaw allows a malicious HTTP server to set "super cookies" in curl that
are then passed back to more origins than what is otherwise allowed or
possible. This allows a site to set cookies that then would get sent to
different and unrelated sites and domains.

It could do this by exploiting a mixed case flaw in curl's function that
verifies a given cookie domain against the Public Suffix List (PSL). For
example a cookie could be set with `domain=co.UK` when the URL used a lower
case hostname `curl.co.uk`, even though `co.uk` is listed as a PSL domain.
Published: 2023-12-07
Score: 6.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No remediation available yet.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-3692-1 curl security update
Debian DSA Debian DSA DSA-5587-1 curl security update
Ubuntu USN Ubuntu USN USN-6535-1 curl vulnerabilities
Ubuntu USN Ubuntu USN USN-6641-1 curl vulnerability
History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00318}

epss

{'score': 0.00432}


Mon, 30 Jun 2025 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-178

Thu, 13 Feb 2025 17:30:00 +0000

Type Values Removed Values Added
Description This flaw allows a malicious HTTP server to set "super cookies" in curl that are then passed back to more origins than what is otherwise allowed or possible. This allows a site to set cookies that then would get sent to different and unrelated sites and domains. It could do this by exploiting a mixed case flaw in curl's function that verifies a given cookie domain against the Public Suffix List (PSL). For example a cookie could be set with `domain=co.UK` when the URL used a lower case hostname `curl.co.uk`, even though `co.uk` is listed as a PSL domain. This flaw allows a malicious HTTP server to set "super cookies" in curl that are then passed back to more origins than what is otherwise allowed or possible. This allows a site to set cookies that then would get sent to different and unrelated sites and domains. It could do this by exploiting a mixed case flaw in curl's function that verifies a given cookie domain against the Public Suffix List (PSL). For example a cookie could be set with `domain=co.UK` when the URL used a lower case hostname `curl.co.uk`, even though `co.uk` is listed as a PSL domain.

Subscriptions

Fedoraproject Fedora
Haxx Curl
Redhat Enterprise Linux Jboss Core Services Logging Openshift Data Foundation Rhel Eus
cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2025-06-30T16:20:37.028Z

Reserved: 2023-10-19T01:00:12.854Z

Link: CVE-2023-46218

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2023-12-07T01:15:07.160

Modified: 2025-06-30T17:15:29.967

Link: CVE-2023-46218

cve-icon Redhat

Severity : Moderate

Publid Date: 2023-12-06T07:00:00Z

Links: CVE-2023-46218 - Bugzilla

cve-icon OpenCVE Enrichment

No data.