strongswan — security advisory
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.
- Products
- strongswan
- Affected versions
- Not specified
- Fixed versions
- 5.7.0-1
- CVEs
- CVE-2018-16151
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 01:31 UTC · Revision 1
Source evidence
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.
osv:DEBIAN-CVE-2018-16151
strongswan
Fixed versions: 5.7.0-1
strongswan
Fixed versions: 5.7.0-1
strongswan
Fixed versions: 5.7.0-1
Complete source record
{
"id": "59fdb55edc5608e7ac72d3fd6dc431e0fa22cdea2cdf32dbd33bd63f97d8f848",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2018-16151",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2018-16151",
"summary": "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.",
"evidence": "osv:DEBIAN-CVE-2018-16151",
"products": [
{
"name": {
"value": "strongswan",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.7.0-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "strongswan",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.7.0-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "strongswan",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.7.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2018-16151",
"aliases": [
"DEBIAN-CVE-2018-16151"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.7.0-1"
}
]
}
],
"package": {
"name": "strongswan",
"purl": "pkg:deb/debian/strongswan?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-16151.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.7.0-1"
}
]
}
],
"package": {
"name": "strongswan",
"purl": "pkg:deb/debian/strongswan?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-16151.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.7.0-1"
}
]
}
],
"package": {
"name": "strongswan",
"purl": "pkg:deb/debian/strongswan?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-16151.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:04:46.739643335Z",
"provider": "osv",
"upstream": [
"CVE-2018-16151"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2018-16151"
]
},
"related_cves": [
{
"value": "CVE-2018-16151",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 423705,
"published_at": "2018-09-26T21:29:01.087+00:00"
}