CVE-2018-16151: 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…

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

None

Integrity

High

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)1.9% · higher than 79% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

DL

Debian Linux · Debian

8.0; 9.0 · source: NVD

ST

Strongswan · Strongswan

4.0.0 through 4.6.4; 5.0.0 before 5.7.0 · source: NVD

UL

Ubuntu Linux · Canonical

14.04; 16.04; 18.04 · source: NVD