strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow

In TRENDnet TEW-WLC100P 2.03b03, the idontcareaboutsecurityanduseaggressivemodepsk option is enabled in the strongSwan configuration file, so that IKE Responders are allowed to use IKEv1 Aggressive Mode with Pre-Shared Keys to conduct offline attacks on the openly transmitted hash of the PSK.

A vulnerability was found in Ruijie EG306MG 3.0(1)B11P309. It has been rated as problematic. This issue affects some unknown processing of the file /etc/strongswan.conf of the component strongSwan. The manipulation of the argument idontcareaboutsecurityanduseaggressivemodepsk leads to missing encryption of sensitive data. The attack may be initiated remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The vendor was contacted early about this disclosure but did not respond in any way.

strongSwan before 5.9.8 allows remote attackers to cause a denial of service in the revocation plugin by sending a crafted end-entity (and intermediate CA) certificate that contains a CRL/OCSP URL that points to a server (under the attacker's control) that doesn't properly respond but (for example) just does nothing after the initial TCP handshake, or sends an excessive amount of application data.

The rsapssparamsparse function in libstrongswan/credentials/keys/signatureparams.c in strongSwan 5.6.1 allows remote attackers to cause a denial of service via a crafted RSASSA-PSS signature that lacks a mask generation function parameter.

In strokesocket.c in strongSwan before 5.6.3, a missing packet length check could allow a buffer underflow, which may lead to resource exhaustion and denial of service while reading from the socket.

IKEv2 in strongSwan 4.0.7 before 5.1.3 allows remote attackers to bypass authentication by rekeying an IKESA during (1) initiation or (2) re-authentication, which triggers the IKESA state to be set to established.

The pluto IKE daemon in Openswan and Strongswan IPsec 2.6 before 2.6.21 and 2.4 before 2.4.14, and Strongswan 4.2 before 4.2.14 and 2.8 before 2.8.9, allows remote attackers to cause a denial of service (daemon crash and restart) via a crafted (1) RUTHERE or (2) RUTHEREACK Dead Peer Detection (DPD) IPsec IKE Notification message that triggers a NULL pointer dereference related to inconsistent ISAKMP state and the lack of a phase2 state association in DPD.

strongSwan before 5.1.2 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon crash) via a crafted IDDERASN1DN ID payload.

In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 through 8, and cause an integer underflow that potentially results in a heap-based buffer overflow.

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKESAINIT message.

In verifyemsapkcs1signature() in gmprsapublickey.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.

In verifyemsapkcs1signature() in gmprsapublickey.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.

Last updated 25 August 2025

Last updated 25 August 2025

The IKE daemon in strongSwan 4.3.x before 4.3.7 and 4.4.x before 4.4.1 does not properly check the return values of snprintf calls, which allows remote attackers to execute arbitrary code via crafted (1) certificate or (2) identity data that triggers buffer overflows.

strongSwan 5.0.2 through 5.1.0 allows remote attackers to cause a denial of service (NULL pointer dereference and charon daemon crash) via a crafted IKEv1 fragmentation packet.

FreeS/WAN 1.x and 2.x, and other related products including superfreeswan 1.x, openswan 1.x before 1.0.6, openswan 2.x before 2.1.4, and strongSwan before 2.1.3, allows remote attackers to authenticate using spoofed PKCS#7 certificates in which a self-signed certificate identifies an alternate Certificate Authority (CA) and spoofed issuer and subject.

charon/sa/tasks/childcreate.c in the charon daemon in strongSWAN before 4.3.1 switches the NULL checks for TSi and TSr payloads, which allows remote attackers to cause a denial of service via an IKEAUTH request without a (1) TSi or (2) TSr traffic selector.

charon/sa/ikesa.c in the charon daemon in strongSWAN before 4.3.1 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an invalid IKESAINIT request that triggers "an incomplete state," followed by a CREATECHILDSA request.

strongSwan 4.3.5 through 5.0.3, when using the OpenSSL plugin for ECDSA signature verification, allows remote attackers to authenticate as other users via an invalid signature.