CVE-2018-0495

MEDIUM

Libgcrypt < 1.7.10 and 1.8.x < 1.8.3 - ECDSA Key Discovery via Memory-Cache Side-Channel Attack

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2018-0495. PoCs published by vaishakhcv, winterwolf32.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2018-0495, a side-channel vulnerability in OpenSSL's ECDSA implementation. The PoC uses a Flush+Reload attack to extract private keys from a vulnerable OpenSSL server.

Description

Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

Exploits (2)

github WORKING POC 1 stars
by vaishakhcv · perlpoc
https://github.com/vaishakhcv/CVE-exploits/tree/master/CVE-2018-0495

This repository contains a functional exploit for CVE-2018-0495, a side-channel vulnerability in OpenSSL's ECDSA implementation. The PoC uses a Flush+Reload attack to extract private keys from a vulnerable OpenSSL server.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Complex
Reliability
Reliable
Target: OpenSSL 1.1.0h
No auth needed
Prerequisites: vulnerable OpenSSL version · local access or co-located execution · specific CPU features for Flush+Reload
devstral-2 · analyzed Feb 27, 2026 Full analysis →
github WORKING POC
by winterwolf32 · perlpoc
https://github.com/winterwolf32/CVE_Exploits-/tree/master/CVE-2018-0495

This repository contains a functional exploit for CVE-2018-0495, a side-channel vulnerability in OpenSSL's ECDSA implementation. The PoC uses a Flush+Reload attack to extract private keys from a vulnerable OpenSSL server.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Complex
Reliability
Reliable
Target: OpenSSL 1.1.0h
No auth needed
Prerequisites: vulnerable OpenSSL version · local access or specific conditions for side-channel attack
devstral-2 · analyzed Feb 27, 2026 Full analysis →

References (21)

Core 21
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1041144
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3850-1/
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1041147
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3689-1/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3689-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3692-2/
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2018/06/msg00013.html
Third Party Advisory vendor-advisory x_refsource_debian
https://www.debian.org/security/2018/dsa-4231
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2018:3505
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3850-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3692-1/
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2018:3221
Patch, Vendor Advisory x_refsource_misc
https://dev.gnupg.org/T4011
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:1297
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:1296
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:1543
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:2237

Scores

CVSS v3 4.7
EPSS 0.0089
EPSS Percentile 54.5%
Attack Vector LOCAL
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Details

CWE
CWE-203
Status published
Products (14)
canonical/ubuntu_linux 12.04
canonical/ubuntu_linux 14.04
canonical/ubuntu_linux 16.04
canonical/ubuntu_linux 17.10
canonical/ubuntu_linux 18.04
canonical/ubuntu_linux 18.10
debian/debian_linux 8.0
debian/debian_linux 9.0
gnupg/libgcrypt < 1.7.10
oracle/traffic_director 11.1.1.9.0
... and 4 more
Published Jun 13, 2018
Tracked Since Feb 18, 2026