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CVE-2018-16151

23
FAUCET Score

CVE-2018-16151 describes a vulnerability in strongSwan versions 4.x and 5.x before 5.7.0, specifically within its RSA implementation based on GMP. This flaw allows a remote attacker to forge PKCS#1 v1.5 signatures by not properly rejecting excess data after the algorithm OID, impacting products like Canonical and Debian distributions of strongSwan. The vulnerability carries a CVSS score of 7.5 (High), indicating a network-based attack with low complexity that can lead to high integrity impact, potentially enabling impersonation during IKEv2 authentication, especially when small public exponents are used. Currently, there is no evidence of active exploitation, no public exploit code available (Metasploit, Nuclei, ExploitDB), and minimal community discussion or media coverage, suggesting a low level of public awareness and exploitation.

Impacted Technologies

VendorProductVersion(s)CPE
>= 4.0.0, <= 4.6.4CPE matchmatch criteria
cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:*
>= 5.0.0, < 5.7.0CPE matchmatch criteria
cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:*
8.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
9.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
14.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*

CVSS Data

CVSS version used by this source: 3.0

7.5HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.0

Exploit Intelligence

EPSS Score
1.89%
Probability of exploitation in next 30 days
EPSS Percentile
77.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0189 is in the 61st percentile among its peer group of 51,551 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Advisories (1)

redhatCVE-2018-16151Moderate

strongswan: authentication bypass in verify_emsa_pkcs1_signature() in gmp_rsa_public_key.c

Sep 24, 2018

References

lists.opensuse.org / opensuse-security-announce/2019-11/msg00077.html
lists.opensuse.org / opensuse-security-announce/2019-12/msg00001.html
lists.opensuse.org / opensuse-security-announce/2020-03/msg00047.html
lists.debian.org / debian-lts-announce/2018/09/msg00032.html
Mailing ListThird Party Advisory
security.gentoo.org / glsa/201811-16
Third Party Advisory
usn.ubuntu.com / 3771-1
Third Party Advisory
debian.org / security/2018/dsa-4305
Third Party Advisory
strongswan.org / blog/2018/09/24/strongswan-vulnerability-%28cve-2018-16151%2C-cve-2018-16152%29.html