CVE-2018-16152

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 in the digestAlgorithm.parameters field during PKCS#1 v1.5 signature verification. Consequently, 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. This is a variant of CVE-2006-4790 and CVE-2014-1568.

Published: 2018-09-26 Last update: 2025-12-03 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-16152 is rated Moderate Risk (58.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.69%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-16152

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 1.52% 1.69% +0.17%
2 2025-12-27 1.69% 1.52% -0.17%
3 2025-12-04 — 1.69% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16152

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-16152

OS Trackers for CVE-2018-16152

vendor priority summary link
alpine — CVE-2018-16152: 1 source package rows (strongswan); 20 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 10. https://security.alpinelinux.org/vuln/CVE-2018-16152
debian not yet assigned CVE-2018-16152 not yet assigned priority: Debian including 1 source packages (strongswan), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-16152
gentoo normal CVE-2018-16152: 1 GLSA(s) (201811-16), 1 atom(s) (net-vpn/strongswan); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-16152
redhat medium — https://access.redhat.com/security/cve/CVE-2018-16152
suse medium CVE-2018-16152 severity moderate: SUSE including 75 source package names (strongswan, strongswan-4.4.0-6.36.12.1, …), 218 product×package rows across 51 product lines (SUSE CaaS Platform 4.5, SUSE Enterprise Storage 4, … (51 product lines)): Fixed 169, Known Not Affected 49. https://www.suse.com/security/cve/CVE-2018-16152/
ubuntu medium CVE-2018-16152 medium priority: Ubuntu including 1 source packages (strongswan), 4 status rows across 4 suites (bionic, trusty, upstream, xenial): released 3, needs-triage 1. https://ubuntu.com/security/CVE-2018-16152

Affected software / configurations for CVE-2018-16152

Vendor Product Version Raw CPE
strongswan strongswan >= 4.0.0, <= 4.6.4 cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:*
strongswan strongswan >= 5.0.0, < 5.7.0 cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*

References for CVE-2018-16152

cvelogic Threat Intelligence