When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure `HTTP://` scheme and perform transfers with hosts like `x.example.com` as well as `example.com` where the first host is a subdomain of the second host. (The HSTS cache either needs to have been populated manually or there needs to have been previous HTTPS accesses done as the cache needs to have entries for the domains involved to trigger this problem.) When `x.example.com` responds with `Strict-Transport-Security:` headers, this bug can make the subdomain's expiry timeout *bleed over* and get set for the parent domain `example.com` in curl's HSTS cache. The result of a triggered bug is that HTTP accesses to `example.com` get converted to HTTPS for a different period of time than what was asked for by the origin server. If `example.com` for example stops supporting HTTPS at its expiry time, curl might then fail to access `http://example.com` until the (wrongly set) timeout expires. This bug can also expire the parent's entry *earlier*, thus making curl inadvertently switch back to insecure HTTP earlier than otherwise intended.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Curl
  • Curl
Haxx
  • Curl

Configuration 1 [-]

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

No data.

References
Link Providers
http://www.openwall.com/lists/oss-security/2024/11/06/2 cve-icon
https://curl.se/docs/CVE-2024-9681.html cve-icon cve-icon
https://curl.se/docs/CVE-2024-9681.json cve-icon cve-icon
https://hackerone.com/reports/2764830 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2024-9681 cve-icon
https://security.netapp.com/advisory/ntap-20241213-0006/ cve-icon
https://www.cve.org/CVERecord?id=CVE-2024-9681 cve-icon
History

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

Type Values Removed Values Added
Metrics epss

{'score': 0.00263}

 epss

{'score': 0.003}

Sat, 12 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00255}

 epss

{'score': 0.00263}

Fri, 13 Dec 2024 14:45:00 +0000

Type Values Removed Values Added
References

Mon, 25 Nov 2024 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Haxx
Haxx curl
Weaknesses CWE-697
CPEs cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
Vendors & Products Haxx
Haxx curl

Fri, 22 Nov 2024 12:00:00 +0000

Type Values Removed Values Added
References

Sat, 16 Nov 2024 01:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1025
References
Metrics threat_severity

None

 threat_severity

Low

Wed, 06 Nov 2024 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Curl
Curl curl
CPEs cpe:2.3:a:curl:curl:*:*:*:*:*:*:*:*
Vendors & Products Curl
Curl curl
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 06 Nov 2024 08:00:00 +0000

Type Values Removed Values Added
Description When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure `HTTP://` scheme and perform transfers with hosts like `x.example.com` as well as `example.com` where the first host is a subdomain of the second host. (The HSTS cache either needs to have been populated manually or there needs to have been previous HTTPS accesses done as the cache needs to have entries for the domains involved to trigger this problem.) When `x.example.com` responds with `Strict-Transport-Security:` headers, this bug can make the subdomain's expiry timeout *bleed over* and get set for the parent domain `example.com` in curl's HSTS cache. The result of a triggered bug is that HTTP accesses to `example.com` get converted to HTTPS for a different period of time than what was asked for by the origin server. If `example.com` for example stops supporting HTTPS at its expiry time, curl might then fail to access `http://example.com` until the (wrongly set) timeout expires. This bug can also expire the parent's entry *earlier*, thus making curl inadvertently switch back to insecure HTTP earlier than otherwise intended.
Title HSTS subdomain overwrites parent cache entry
References
cve-icon MITRE

Status: PUBLISHED

Assigner: curl

Published: 2024-11-06T07:47:20.162Z

Updated: 2024-12-13T13:09:28.285Z

Reserved: 2024-10-09T07:57:47.318Z

Link: CVE-2024-9681

cve-icon Vulnrichment

Updated: 2024-12-13T13:09:28.285Z

cve-icon NVD

Status : Modified

Published: 2024-11-06T08:15:03.740

Modified: 2024-12-13T14:15:22.953

Link: CVE-2024-9681

cve-icon Redhat

Severity : Low

Publid Date: 2024-11-06T00:00:00Z

Links: CVE-2024-9681 - Bugzilla