CVE-2025-65500 — MEDIUM (4.3)

Vulnerability Description

NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS handshake that triggers SSL_get_SSL_CTX() to return NULL.

CVSS Score

4.3

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

LOW

Affected Products

Vendor	Product	Versions
Libcoap	Libcoap	4.3.5

Related Weaknesses (CWE)

CWE-476

References

https://github.com/obgm/libcoap/issues/1746Issue Tracking
https://github.com/obgm/libcoap/pull/1750Issue TrackingPatch

FAQ

What is CVE-2025-65500?

CVE-2025-65500 is a vulnerability with a CVSS score of 4.3 (MEDIUM). NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS handshake that triggers SSL_...

How severe is CVE-2025-65500?

CVE-2025-65500 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-65500?

Check the references section above for vendor advisories and patch information. Affected products include: Libcoap Libcoap.