Null Pointer Dereference in `coap_client_exchange_blockwise2` function in Keith Cullen…
Priority HIGH 81CWE-476Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
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`.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00784 56th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:keith-cullen:freecoap:1.0:*:*:*:*:*:*:* | 1.0 | Vulnerable | Keith-cullen |
- cpe:2.3:a:keith-cullen:freecoap:1.0:*:*:*:*:*:*:* Versions 1.0 Vulnerable ·Keith-cullen
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2024-40493
- 2026-10-03 Alias added: GHSA-cr59-3vcq-rrw6
References
More Keith-cullen Freecoap vulnerabilities
- TI-2024-26957 Buffer Overflow in coap_msg.c in FreeCoAP allows remote attackers to execute arbitrary… CVSS 3.1CRITICAL 9.8
- TI-2024-20445 An issue in the server_handle_regular function of the test_coap_server.c file within the… CVSS 3.1HIGH 8.2
- TI-2024-20446 An issue in coap_msg.c in Keith Cullen's FreeCoAP v.0.7 allows remote attackers to cause… CVSS 3.1CRITICAL 9.1
Sources
- CVE-2024-40493 · CVE Program
- CVE-2024-40493 · NVD
- FIRST EPSS
- GHSA-cr59-3vcq-rrw6 · GitHub Advisory Database · CC BY 4.0
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