CVE-2024-9681: 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

Medium severity · published Nov 6, 2024

CVE-2024-9681

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

6.5

CVSS

EPSS

On KEV

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.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L

Attack vector

Network

Complexity

High

Privileges

None

User interaction

None

Confidentiality

None

Integrity

High

Availability

Low

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)2.0% · higher than 81% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

Curl · Haxx

7.74.0 before 8.11.0 · source: NVD

In the news

VulnerabilityHigh

Siemens SINEC OS

View CSAF Summary SINEC OS before V3.3 contains third-party components with multiple vulnerabilities. Siemens has released new versions for the affected products and recommends to update to the latest versions. The following versions of Siemens SINEC OS are affected: RUGGEDCOM RST2428P (6GK6242-6PA00) vers:intdot/<3.3 (CVE-2022-48174, CVE-2023-7256, CVE-2023-39810, CVE-2023-42363, CVE-2023-42364, CVE-2023-42365, CVE-2023-42366, CVE-2024-6197, CVE-2024-6874, CVE-2024-7264, CVE-2024-8006, CVE-2024-8096, CVE-2024-9681, CVE-2024-11053, CVE-2024-12718, CVE-2024-41996, CVE-2024-47619, CVE-2024-52533, CVE-2025-0167, CVE-2025-0665, CVE-2025-0725, CVE-2025-1390, CVE-2025-3360, CVE-2025-4138, CVE-2025-4330, CVE-2025-4373, CVE-2025-4435, CVE-2025-4516, CVE-2025-4517, CVE-2025-6141, CVE-2025-9086, CVE-2025-9230, CVE-2025-9231, CVE-2025-9232, CVE-2025-10148, CVE-2025-27587, CVE-2025-32433, CVE-2025-38084, CVE-2025-38085, CVE-2025-38086, CVE-2025-38345, CVE-2025-38350, CVE-2025-38498, CVE-2025-39839, CVE-2025-39841, CVE-2025-39846, CVE-2025-39853, CVE-2025-39860, CVE-2025-39864, CVE-2025-39865, CVE-2025-59375) SCALANCE XCH328 (6GK5328-4TS01-2EC2) vers:intdot/<3.3 (CVE-2022-48174, CVE-2023-7256, CVE-2023-39810, CVE-2023-42363, CVE-2023-42364, CVE-2023-42365, CVE-2023-42366, CVE-2024-6197, CVE-2024-6874, CVE-2024-7264, CVE-2024-8006, CVE-2024-8096, CVE-2024-9681, CVE-2024-11053, CVE-2024-12718, CVE-2024-41996, CVE-2024-47619, CVE-2024-52533, CVE-2025-0167, CVE-2025-0665...

CVE-2022-48174 CVE-2023-7256 CVE-2023-39810

Feb 12, 2026·CISA Advisories

Affected product

Curl

Haxx

All Curl CVEs

References

NVD

https://nvd.nist.gov/vuln/detail/CVE-2024-9681

CVE.org

https://www.cve.org/CVERecord?id=CVE-2024-9681

Patch