CVE-2018-16151

HIGH

strongSwan 4.x-5.x - Cryptographic Signature Verification Bypass via Excess Data in PKCS#1 v1.5

Title source: llm
STIX 2.1

Description

In verify_emsa_pkcs1_signature() in gmp_rsa_public_key.c in the gmp plugin in strongSwan 4.x and 5.x before 5.7.0, the RSA implementation based on GMP does not reject excess data after the encoded algorithm OID during PKCS#1 v1.5 signature verification. Similar to the flaw in the same version of strongSwan regarding digestAlgorithm.parameters, a remote attacker can forge signatures when small public exponents are being used, which could lead to impersonation when only an RSA signature is used for IKEv2 authentication.

References (8)

Core 8
Core References
Third Party Advisory vendor-advisory x_refsource_debian
https://www.debian.org/security/2018/dsa-4305
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/201811-16
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2018/09/msg00032.html
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3771-1/

Scores

CVSS v3 7.5
EPSS 0.0168
EPSS Percentile 82.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-347
Status published
Products (6)
canonical/ubuntu_linux 14.04
canonical/ubuntu_linux 16.04
canonical/ubuntu_linux 18.04
debian/debian_linux 8.0
debian/debian_linux 9.0
strongswan/strongswan 4.0.0 - 4.6.4
Published Sep 26, 2018
Tracked Since Feb 18, 2026