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.
https://github.com/obgm/libcoap/pull/1750
https://github.com/obgm/libcoap/issues/1746
Source: Mitre, NVD
Published: 2025-11-24
Updated: 2025-11-25
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 4.3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS: 0.00088