CVE-2018-8970

HIGH

LibreSSL 2.7.0 - Improper Certificate Validation via Zero-Length Hostname

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2018-8970. PoCs published by tiran.

AI-analyzed exploit summary This PoC demonstrates CVE-2018-8970, a vulnerability in OpenSSL where the host name verification does not correctly handle wildcards, allowing an attacker to bypass certificate validation. The code connects to a server and verifies the host name against a mismatched certificate, exploiting the flaw.

Description

The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate. NOTE: the LibreSSL documentation indicates that this special case is supported, but the BoringSSL documentation does not.

Exploits (1)

nomisec WORKING POC 1 stars
by tiran · poc
https://github.com/tiran/CVE-2018-8970

This PoC demonstrates CVE-2018-8970, a vulnerability in OpenSSL where the host name verification does not correctly handle wildcards, allowing an attacker to bypass certificate validation. The code connects to a server and verifies the host name against a mismatched certificate, exploiting the flaw.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: OpenSSL (versions before 1.1.1)
No auth needed
Prerequisites: OpenSSL library with vulnerable version · Network access to a server with a mismatched certificate
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (3)

Core 3

Scores

CVSS v3 7.4
EPSS 0.0071
EPSS Percentile 72.5%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Details

CWE
CWE-295
Status published
Products (1)
openbsd/libressl 2.7.0
Published Mar 24, 2018
Tracked Since Feb 18, 2026