GNU Gnutls

The _gnutls_server_name_recv_params function in lib/ext_server_name.c in libgnutls in gnutls-serv in GnuTLS before 2.2.4 does not properly calculate the number of Server Names in a TLS 1.0 Client Hello message during extension handling, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a zero value for the length of Server Names, which leads to a buffer overflow in session resumption data in the pack_security_parameters function, aka GNUTLS-SA-2008-1-1.

The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft Internet Information Services (IIS) 7.0, mod_ssl in the Apache HTTP Server 2.2.14 and earlier, OpenSSL before 0.9.8l, GnuTLS 2.8.5 and earlier, Mozilla Network Security Services (NSS) 3.12.4 and earlier, multiple Cisco products, and other products, does not properly associate renegotiation handshakes with an existing connection, which allows man-in-the-middle attackers to insert data into HTTPS sessions, and possibly other types of sessions protected by TLS or SSL, by sending an unauthenticated request that is processed retroactively by a server in a post-renegotiation context, related to a "plaintext injection" attack, aka the "Project Mogul" issue.

Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attackers to have unspecified impact via crafted policy language information in an X.509 certificate with a Proxy Certificate Information extension.

Stack-based buffer overflow in the cdk_pk_get_keyid function in lib/opencdk/pubkey.c in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attackers to have unspecified impact via a crafted OpenPGP certificate.

Multiple heap-based buffer overflows in the read_attribute function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allow remote attackers to have unspecified impact via a crafted OpenPGP certificate.

A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.

A flaw was found in gnutls. A use after free issue in client_send_params in lib/ext/pre_shared_key.c may lead to memory corruption and other potential consequences.

Gnutls: gnutls: authentication bypass via nul character in username

The _gnutls_recv_client_kx_message function in lib/gnutls_kx.c in libgnutls in gnutls-serv in GnuTLS before 2.2.4 continues to process Client Hello messages within a TLS message after one has already been processed, which allows remote attackers to cause a denial of service (NULL dereference and crash) via a TLS message containing multiple Client Hello messages, aka GNUTLS-SA-2008-1-2.

Gnutls: gnutls: denial of service via dtls zero-length fragment

Gnutls: vulnerability in gnutls othername san export

Gnutls: vulnerability in gnutls certtool template parsing

X.509 Certificate Signature Verification in Gnu transport layer security library (GnuTLS) 1.0.16 allows remote attackers to cause a denial of service (CPU consumption) via certificates containing long chains and signed with large RSA keys.

Use-after-free vulnerability in the _gnutls_handshake_hash_buffers_clear function in lib/gnutls_handshake.c in libgnutls in GnuTLS 2.3.5 through 2.4.0 allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via TLS transmission of data that is improperly used when the peer calls gnutls_handshake within a normal session, leading to attempted access to a deallocated libgcrypt handle.

A vulnerability was found in gnutls versions from 3.5.8 before 3.6.7. A memory corruption (double free) vulnerability in the certificate verification API. Any client or server application that verifies X.509 certificates with GnuTLS 3.5.8 or later is affected.

The stream reading functions in lib/opencdk/read-packet.c in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allow remote attackers to cause a denial of service (out-of-memory error and crash) via a crafted OpenPGP certificate.

Double free vulnerability in libgnutls in GnuTLS before 3.0.14 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted certificate list.

Double free vulnerability in lib/x509/x509_ext.c in GnuTLS before 3.3.14 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted CRL distribution point.

lib/gnutls_pk.c in libgnutls in GnuTLS 2.5.0 through 2.6.5 generates RSA keys stored in DSA structures, instead of the intended DSA keys, which might allow remote attackers to spoof signatures on certificates or have unspecified other impact by leveraging an invalid DSA key.

The asn1_get_bit_der function in GNU Libtasn1 before 3.6 does not properly report an error when a negative bit length is identified, which allows context-dependent attackers to cause out-of-bounds access via crafted ASN.1 data.

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.

GnuTLS version 3.5.12 and earlier is vulnerable to a NULL pointer dereference while decoding a status response TLS extension with valid contents. This could lead to a crash of the GnuTLS server application.

It was discovered in gnutls before version 3.6.7 upstream that there is an uninitialized pointer access in gnutls versions 3.6.3 or later which can be triggered by certain post-handshake messages.

The gnutls_x509_crt_get_serial function in the GnuTLS library before 1.2.1, when running on big-endian, 64-bit platforms, calls the asn1_read_value with a pointer to the wrong data type and the wrong length value, which allows remote attackers to bypass the certificate revocation list (CRL) check and cause a stack-based buffer overflow via a crafted X.509 certificate, related to extraction of a serial number.

GnuTLS before 2017-02-20 has an out-of-bounds write caused by an integer overflow and heap-based buffer overflow related to the cdk_pkt_read function in opencdk/read-packet.c. This issue (which is a subset of the vendor's GNUTLS-SA-2017-3 report) is fixed in 3.5.10.

The gnutls_ocsp_resp_check_crt function in lib/x509/ocsp.c in GnuTLS before 3.4.15 and 3.5.x before 3.5.4 does not verify the serial length of an OCSP response, which might allow remote attackers to bypass an intended certificate validation mechanism via vectors involving trailing bytes left by gnutls_malloc.

The "GNUTLS_KEYLOGFILE" environment variable in gnutls 3.4.12 allows remote attackers to overwrite and corrupt arbitrary files in the filesystem.

libgnutls in GnuTLS before 2.8.2 does not properly handle a '\0' character in a domain name in the subject's (1) Common Name (CN) or (2) Subject Alternative Name (SAN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.

A vulnerability found in gnutls. This security flaw happens because of a double free error occurs during verification of pkcs7 signatures in gnutls_pkcs7_verify function.

Gnutls: incomplete fix for cve-2023-5981

GnuTLS before 3.3.13 does not validate that the signature algorithms match when importing a certificate.

Gnutls: rejects certificate chain with distributed trust

Gnutls: gnutls: denial of service via dtls packet reordering vulnerability

Gnutls: gnutls: remote denial of service via crafted clienthello with invalid psk binder

GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.

GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography for DTLS. The earliest affected version is 3.6.3 (2018-07-16) because of an error in a 2017-10-06 commit. The DTLS client always uses 32 '\0' bytes instead of a random value, and thus contributes no randomness to a DTLS negotiation. This breaks the security guarantees of the DTLS protocol.

A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS. This side-channel can be sufficient to recover the key encrypted in the RSA ciphertext across a network in a Bleichenbacher style attack. To achieve a successful decryption the attacker would need to send a large amount of specially crafted messages to the vulnerable server. By recovering the secret from the ClientKeyExchange message, the attacker would be able to decrypt the application data exchanged over that connection.

Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison

Buffer overflow in the read_server_hello function in lib/gnutls_handshake.c in GnuTLS before 3.1.25, 3.2.x before 3.2.15, and 3.3.x before 3.3.4 allows remote servers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a long session id in a ServerHello message.

Mutt 1.5.19, when linked against (1) OpenSSL (mutt_ssl.c) or (2) GnuTLS (mutt_ssl_gnutls.c), allows connections when only one TLS certificate in the chain is accepted instead of verifying the entire chain, which allows remote attackers to spoof trusted servers via a man-in-the-middle attack.