CVE-2025-65493: libcoap Null Dereference — Fix

Description

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

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CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
libcoap	libcoap	All

References

Advisories & Patches

https://github.com/obgm/libcoap/pull/1750

Other References

https://github.com/obgm/libcoap/issues/1743

Frequently Asked Questions

What is CVE-2025-65493? +

NULL pointer dereference in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS/TLS connection that triggers BIO_get_data() to return NULL. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-65493? +

CVE-2025-65493 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-65493? +

CVE-2025-65493 affects products from libcoap, specifically: libcoap. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-65493? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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