Libreswan: >> Libreswan >> 3.21 Security Vulnerabilities
Libreswan, via the function RSA_authenticate_hash_signature_raw_rsa(), did not correctly verify the length of the authentication hash when the SIG payload of an IKEv1 packet was encoded using PKCS #1 RSA Encryption as per RFC 2313. A remote attacker can use a variation on the Bleichenbacher attack to forge the SIG payload when small public exponents are being used (e.g., e=3), which could lead to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the SIG payload, could trigger an assertion leading to denial-of-service. The daemon aborts and restarts; continued exploitation causes sustained denial of service. Remote code execution is not possible. X.509 certificate verifications of remote IKE peers are not affected.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-02
Libreswan, via the function RSA_authenticate_hash_signature_pkcs1_1_5_rsa(), did not correctly verify the DER encoding of the ASN.1 digest when the IKEv2 AUTH payload was encoded using RSASSA-PKCS1-v1_5 (RFC 8017). A remote attacker can use a variation on the Bleichenbacher attack to forge the AUTH payload when small public exponents are used (e.g., e=3), leading to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the AUTH payload, could trigger an assertion leading to denial-of-service. The daemon aborts and restarts; continued exploitation causes sustained denial of service. Remote code execution is not possible. X.509 certificate verifications of the remote IKE peer are not affected.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-02
An issue was discovered in Libreswan before 4.12. When an IKEv2 Child SA REKEY packet contains an invalid IPsec protocol ID number of 0 or 1, an error notify INVALID_SPI is sent back. The notify payload's protocol ID is copied from the incoming packet, but the code that verifies outgoing packets fails an assertion that the protocol ID must be ESP (2) or AH(3) and causes the pluto daemon to crash and restart. NOTE: the earliest affected version is 3.20.
CVSS Score
6.5
EPSS Score
0.007
Published
2023-08-25
An issue was discovered in Libreswan 3.x and 4.x before 4.12. When an IKEv1 ISAKMP SA Informational Exchange packet contains a Delete/Notify payload followed by further Notifies that act on the ISAKMP SA, such as a duplicated Delete/Notify message, a NULL pointer dereference on the deleted state causes the pluto daemon to crash and restart.
CVSS Score
6.5
EPSS Score
0.007
Published
2023-08-25
The Libreswan Project has found a vulnerability in the processing of IKEv1 informational exchange packets which are encrypted and integrity protected using the established IKE SA encryption and integrity keys, but as a receiver, the integrity check value was not verified. This issue affects versions before 3.29.
CVSS Score
3.1
EPSS Score
0.005
Published
2019-06-12
In Libreswan 3.27 an assertion failure can lead to a pluto IKE daemon restart. An attacker can trigger a NULL pointer dereference by initiating an IKEv2 IKE_SA_INIT exchange, followed by a bogus INFORMATIONAL exchange instead of the normallly expected IKE_AUTH exchange. This affects send_v2N_spi_response_from_state() in programs/pluto/ikev2_send.c that will then trigger a NULL pointer dereference leading to a restart of libreswan.
CVSS Score
7.5
EPSS Score
0.027
Published
2019-05-24