How severe is CVE-2024-40493?

CVE-2024-40493 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2024-40493 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-40493?

CVE-2024-40493 affects Keith-cullen Freecoap. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-40493?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2024-40493 have an EU (EUVD) identifier?

Yes. CVE-2024-40493 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-38480.

When was CVE-2024-40493 published?

CVE-2024-40493 was published on 2024-10-22 and last updated on 2026-06-17.

CVE-2024-40493

CVE-2024-40493 is a critical-severity vulnerability in Keith-cullen Freecoap with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-38480
Weakness: CWE-476
Affected product: Keith-cullen Freecoap
Published: 2024-10-22
Last modified: 2026-06-17

Description

Null Pointer Dereference in `coap_client_exchange_blockwise2` function in Keith Cullen FreeCoAP 1.0 allows remote attackers to cause a denial of service and potentially execute arbitrary code via a specially crafted CoAP packet that causes `coap_msg_get_payload(resp)` to return a null pointer, which is then dereferenced in a call to `memcpy`.

Frequently asked questions

What is CVE-2024-40493?: Null Pointer Dereference in `coap_client_exchange_blockwise2` function in Keith Cullen FreeCoAP 1.0 allows remote attackers to cause a denial of service and potentially execute arbitrary code via a specially crafted CoAP packet that causes `coap_msg_get_payload(resp)` to return a null pointer, which is then dereferenced in a call to `memcpy`.
How severe is CVE-2024-40493?: CVE-2024-40493 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2024-40493 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-40493?: CVE-2024-40493 affects Keith-cullen Freecoap. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-40493?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2024-40493 have an EU (EUVD) identifier?: Yes. CVE-2024-40493 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-38480.
When was CVE-2024-40493 published?: CVE-2024-40493 was published on 2024-10-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:keith-cullen:freecoap:1.0:*:*:*:*:*:*:*

More vulnerabilities in Keith-cullen Freecoap

CVE-2024-40494 — Critical (CVSS 9.8): Buffer Overflow in coap_msg.c in FreeCoAP allows remote attackers to execute arbitrary code or cause a denial of…
CVE-2024-31030 — Critical (CVSS 9.1): An issue in coap_msg.c in Keith Cullen's FreeCoAP v.0.7 allows remote attackers to cause a Denial of Service or…
CVE-2024-31029 — High (CVSS 8.2): An issue in the server_handle_regular function of the test_coap_server.c file within the FreeCoAP project allows remote…

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