Improper Authentication in strongSwan - CVE-2018-16151

 

Improper Authentication in strongSwan - CVE-2018-16151

Published: November 5, 2018


Vulnerability identifier: #VU15722
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2018-16151
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability: No public exploit available
Vendor: strongswan.org
Affected software:
strongSwan

Detailed vulnerability description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in RSA implementation based on GMP (verify_emsa_pkcs1_signature() in gmp_rsa_public_key.c) within the gmp plugin that does not reject excess data after the encoded algorithm OID during PKCS#1 v1.5 signature verification. A remote attacker can forge signatures when small public exponents are being used and impersonate the victim.

Successful exploitation of the vulnerability may allow an attacker to take full control over victim's session but requires that only an RSA signature is used for IKEv2 authentication.


How to mitigate CVE-2018-16151

Install updates from vendor's website.

Sources