Vulnerability in Curl

CVE-2023-46218

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.

EPSS: 0.017 (74.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-46218?
CVE-2023-46218 is a medium-severity vulnerability in Curl, classified under Improper Handling of Case Sensitivity. CVSS score: 6.5/10. Published 2023-12-07.
How severe is CVE-2023-46218?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2023-46218 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.