CVE-2024-9681: HSTS subdomain overwrites parent cache entry
Noroxi assessment
Priority: Monitor (action score 27/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.9% (FIRST EPSS); higher than 80.5% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: azl3 cmake 3.30.3-4 on Azure Linux 3.0 3.30.3-4; azl3 cmake 3.30.3-6 on Azure Linux 3.0 3.30.3-4; azl3 curl 8.8.0-4 on Azure Linux 3.0 8.8.0-4.
Low priority for now. Upgrade to azl3 cmake 3.30.3-4 on Azure Linux 3.0 3.30.3-4; azl3 cmake 3.30.3-6 on Azure Linux 3.0 3.30.3-4; azl3 curl 8.8.0-4 on Azure Linux 3.0 8.8.0-4 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Nov 6, 2024
- Updated
- Jun 17, 2026
- EPSS
- 1.9% · 80th percentile
- CWE
- CWE-697
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 1.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| haxx | curl | cpe:2.3:a:haxx:curl |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- haxx curl7.74.0 and later · before 8.11.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (curl). Independent of NVD's CPE analysis and usually ahead of it.
curl curl
- 8.10.1 and later · up to and including 8.10.1affected · semver
- 8.10.0 and later · up to and including 8.10.0affected · semver
- 8.9.1 and later · up to and including 8.9.1affected · semver
- 8.9.0 and later · up to and including 8.9.0affected · semver
- 8.8.0 and later · up to and including 8.8.0affected · semver
- 8.7.1 and later · up to and including 8.7.1affected · semver
- 8.7.0 and later · up to and including 8.7.0affected · semver
- 8.6.0 and later · up to and including 8.6.0affected · semver
- 8.5.0 and later · up to and including 8.5.0affected · semver
- 8.4.0 and later · up to and including 8.4.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.18 | curl | from 7.74.0 · before 8.11.0-r0 | 8.11.0-r0 |
| Debian:12 | curl | before 7.88.1-10+deb12u9 | 7.88.1-10+deb12u9 |
| Debian:13 | curl | before 8.11.0-1 | 8.11.0-1 |
| openSUSE:Leap 15.6 | curl | before 8.6.0-150600.4.12.1 | 8.6.0-150600.4.12.1 |
| openSUSE:Leap Micro 5.5 | curl | before 8.0.1-150400.5.56.1 | 8.0.1-150400.5.56.1 |
| openSUSE:Tumbleweed | curl | before 8.11.0-1.1 | 8.11.0-1.1 |
| SUSE:Linux Enterprise Installer Updates 15 SP4 | curl | before 8.0.1-150400.5.56.1 | 8.0.1-150400.5.56.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | curl | before 8.6.0-150600.4.12.1 | 8.6.0-150600.4.12.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | curl | before 8.0.1-11.98.1 | 8.0.1-11.98.1 |
| SUSE:Linux Micro 6.0 | curl | before 8.6.0-4.1 | 8.6.0-4.1 |
| SUSE:Linux Micro 6.1 | curl | before 8.12.1-slfo.1.1_1.1 | 8.12.1-slfo.1.1_1.1 |
Same product
haxx: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-22901curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session t51Plan
- CVE-2023-38039When curl retrieves an HTTP response, it stores the incoming headers so that
they can be accessed later via the libcurl headers API.47Plan
- CVE-2024-2398HTTP/2 push headers memory-leak45Plan
Published before and after this one in the same product
- ← EarlierCVE-2024-2466Mar 27, 2024 · TLS certificate check bypass with mbedTLS26Monitor
- ← EarlierCVE-2024-8096Sep 11, 2024 · OCSP stapling bypass with GnuTLS26Monitor
- Later →CVE-2024-11053Dec 11, 2024 · netrc and redirect credential leak14Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| azl3 cmake 3.30.3-4 on Azure Linux 3.0 | 3.30.3-4 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 cmake 3.30.3-6 on Azure Linux 3.0 | 3.30.3-4 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 curl 8.8.0-4 on Azure Linux 3.0 | 8.8.0-4 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 mysql 8.0.40-5 on Azure Linux 3.0 | 8.0.40-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 mysql 8.0.40-6 on Azure Linux 3.0 | 8.0.40-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 tensorflow 2.16.1-7 on Azure Linux 3.0 | 2.16.1-7 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 cmake 3.21.4-16 on CBL Mariner 2.0 | 3.21.4-16 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 cmake 3.21.4-17 on CBL Mariner 2.0 | 3.21.4-16 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 cmake 3.21.4-17 on CBL-Mariner 2.0 | 3.21.4-16 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 curl 8.8.0-5 on CBL Mariner 2.0 | 8.8.0-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 curl 8.8.0-6 on CBL Mariner 2.0 | 8.8.0-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 curl 8.8.0-6 on CBL-Mariner 2.0 | 8.8.0-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 mysql 8.0.40-3 on CBL Mariner 2.0 | 8.0.40-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 mysql 8.0.40-4 on CBL Mariner 2.0 | 8.0.40-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 mysql 8.0.40-4 on CBL-Mariner 2.0 | 8.0.40-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 rust 1.72.0-10 on CBL Mariner 2.0 | 1.72.0-10 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 rust 1.72.0-10 on CBL-Mariner 2.0 | 1.72.0-10 · CBL-Mariner Releases | Microsoft (MSRC) |
| alpine:curl | 8.11.0-r0 · Alpine:v3.18 | Package registry (OSV) |
| debian:curl | 7.88.1-10+deb12u9 · Debian:12 | Package registry (OSV) |
| opensuse:curl | 8.6.0-150600.4.12.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| suse:curl | 8.6.0-150600.4.12.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- newfunctionfinder
- Daniel Stenbergremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- Low
Weakness class (CWE)
CWE-697 · Incorrect ComparisonCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Command DelimitersCAPEC-15likelihood: High · High
- Flash InjectionCAPEC-182likelihood: High · Medium
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- Leverage Alternate EncodingCAPEC-267likelihood: High · High
- Using Leading 'Ghost' Character Sequences to Bypass Input FiltersCAPEC-3likelihood: Medium · Medium
ATT&CK techniques
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (11 more)Show less
- curl.se/docs/CVE-2024-9681.json
- seclists.org/fulldisclosure/2025/Apr/10
- seclists.org/fulldisclosure/2025/Apr/11
- seclists.org/fulldisclosure/2025/Apr/12
- seclists.org/fulldisclosure/2025/Apr/13
- seclists.org/fulldisclosure/2025/Apr/4
- seclists.org/fulldisclosure/2025/Apr/5
- seclists.org/fulldisclosure/2025/Apr/8
- seclists.org/fulldisclosure/2025/Apr/9
- www.openwall.com/lists/oss-security/2024/11/06/2
- security.netapp.com/advisory/ntap-20241213-0006/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.