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
lowercase hostname curl.co.uk
, even though co.uk
is listed as a PSL
domain.
{ "CWE": { "id": "CWE-201", "desc": "Information Exposure Through Sent Data" }, "award": { "amount": "2540", "currency": "USD" }, "URL": "https://curl.se/docs/CVE-2023-46218.json", "package": "curl", "severity": "Medium", "issue": "https://hackerone.com/reports/2212193", "www": "https://curl.se/docs/CVE-2023-46218.html", "last_affected": "8.4.0" }