The do_free_upto function in crypto/cms/cms_smime.c in OpenSSL before 0.9.8zg, 1.0.0 before 1.0.0s, 1.0.1 before 1.0.1n, and 1.0.2 before 1.0.2b allows remote attackers to cause a denial of service (infinite loop) via vectors that trigger a NULL value of a BIO data structure, as demonstrated by an unrecognized X.660 OID for a hash function.

The ssl3_get_key_exchange function in ssl/s3_clnt.c in OpenSSL 1.0.2 before 1.0.2e allows remote servers to cause a denial of service (segmentation fault) via a zero p value in an anonymous Diffie-Hellman (DH) ServerKeyExchange message.

The ASN1_item_ex_d2i function in crypto/asn1/tasn_dec.c in OpenSSL before 0.9.8zf, 1.0.0 before 1.0.0r, 1.0.1 before 1.0.1m, and 1.0.2 before 1.0.2a does not reinitialize CHOICE and ADB data structures, which might allow attackers to cause a denial of service (invalid write operation and memory corruption) by leveraging an application that relies on ASN.1 structure reuse.

The dtls1_listen function in d1_lib.c in OpenSSL 1.0.2 before 1.0.2a does not properly isolate the state information of independent data streams, which allows remote attackers to cause a denial of service (application crash) via crafted DTLS traffic, as demonstrated by DTLS 1.0 traffic to a DTLS 1.2 server.

The sigalgs implementation in t1_lib.c in OpenSSL 1.0.2 before 1.0.2a allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) by using an invalid signature_algorithms extension in the ClientHello message during a renegotiation.

The PKCS#7 implementation in OpenSSL before 0.9.8zf, 1.0.0 before 1.0.0r, 1.0.1 before 1.0.1m, and 1.0.2 before 1.0.2a does not properly handle a lack of outer ContentInfo, which allows attackers to cause a denial of service (NULL pointer dereference and application crash) by leveraging an application that processes arbitrary PKCS#7 data and providing malformed data with ASN.1 encoding, related to crypto/pkcs7/pk7_doit.c and crypto/pkcs7/pk7_lib.c.

The X509_to_X509_REQ function in crypto/x509/x509_req.c in OpenSSL before 0.9.8zf, 1.0.0 before 1.0.0r, 1.0.1 before 1.0.1m, and 1.0.2 before 1.0.2a might allow attackers to cause a denial of service (NULL pointer dereference and application crash) via an invalid certificate key.

OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted DTLS message that is processed with a different read operation for the handshake header than for the handshake body, related to the dtls1_get_record function in d1_pkt.c and the ssl3_read_n function in s3_pkt.c.

A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server version 2.4.37 when using OpenSSL version 1.1.1 or later, due to an interaction in changes to handling of renegotiation attempts.

Memory leak in d1_both.c in the DTLS implementation in OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i allows remote attackers to cause a denial of service (memory consumption) via zero-length DTLS fragments that trigger improper handling of the return value of a certain insert function.

Double free vulnerability in d1_both.c in the DTLS implementation in OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i allows remote attackers to cause a denial of service (application crash) via crafted DTLS packets that trigger an error condition.

The ssl23_get_client_hello function in s23_srvr.c in OpenSSL 0.9.8zc, 1.0.0o, and 1.0.1j does not properly handle attempts to use unsupported protocols, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an unexpected handshake, as demonstrated by an SSLv3 handshake to a no-ssl3 application with certain error handling. NOTE: this issue became relevant after the CVE-2014-3568 fix.

Multiple integer overflows in OpenSSL 1.0.1 before 1.0.1s and 1.0.2 before 1.0.2g allow remote attackers to cause a denial of service (heap memory corruption or NULL pointer dereference) or possibly have unspecified other impact via a long digit string that is mishandled by the (1) BN_dec2bn or (2) BN_hex2bn function, related to crypto/bn/bn.h and crypto/bn/bn_print.c.

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

If an SSL/TLS server or client is running on a 32-bit host, and a specific cipher is being used, then a truncated packet can cause that server or client to perform an out-of-bounds read, usually resulting in a crash. For OpenSSL 1.1.0, the crash can be triggered when using CHACHA20/POLY1305; users should upgrade to 1.1.0d. For Openssl 1.0.2, the crash can be triggered when using RC4-MD5; users who have not disabled that algorithm should update to 1.0.2k.

In OpenSSL 1.1.0 before 1.1.0d, if a malicious server supplies bad parameters for a DHE or ECDHE key exchange then this can result in the client attempting to dereference a NULL pointer leading to a client crash. This could be exploited in a Denial of Service attack.

A denial of service flaw was found in OpenSSL 0.9.8, 1.0.1, 1.0.2 through 1.0.2h, and 1.1.0 in the way the TLS/SSL protocol defined processing of ALERT packets during a connection handshake. A remote attacker could use this flaw to make a TLS/SSL server consume an excessive amount of CPU and fail to accept connections from other clients.

The TS_OBJ_print_bio function in crypto/ts/ts_lib.c in the X.509 Public Key Infrastructure Time-Stamp Protocol (TSP) implementation in OpenSSL through 1.0.2h allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted time-stamp file that is mishandled by the "openssl ts" command.