Openssl » Openssl : Security Vulnerabilities, CVEs,

OpenSSL and SSLeay allow remote attackers to reuse SSL sessions and bypass access controls.

OpenSSL 0.9.4 and OpenSSH for FreeBSD do not properly check for the existence of the /dev/random or /dev/urandom devices, which are absent on FreeBSD Alpha systems, which causes them to produce weak keys which may be more easily broken.

crypto/rsa/rsa_gen.c in OpenSSL before 0.9.6 mishandles C bitwise-shift operations that exceed the size of an expression, which makes it easier for remote attackers to defeat cryptographic protection mechanisms by leveraging improper RSA key generation on 64-bit HP-UX platforms.

The Pseudo-Random Number Generator (PRNG) in SSLeay and OpenSSL before 0.9.6b allows attackers to use the output of small PRNG requests to determine the internal state information, which could be used by attackers to predict future pseudo-random numbers.

OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, does not properly handle ASCII representations of integers on 64 bit platforms, which could allow attackers to cause a denial of service and possibly execute arbitrary code.

Buffer overflows in OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, allow remote attackers to execute arbitrary code via (1) a large client master key in SSL2 or (2) a large session ID in SSL3.

Buffer overflow in OpenSSL 0.9.7 before 0.9.7-beta3, with Kerberos enabled, allows attackers to execute arbitrary code via a long master key.

The ASN1 library in OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, allows remote attackers to cause a denial of service via invalid encodings.

OpenSSL 0.9.6e uses assertions when detecting buffer overflow attacks instead of less severe mechanisms, which allows remote attackers to cause a denial of service (crash) via certain messages that cause OpenSSL to abort from a failed assertion, as demonstrated using SSLv2 CLIENT_MASTER_KEY messages, which are not properly handled in s2_srvr.c.

ssl3_get_record in s3_pkt.c for OpenSSL before 0.9.7a and 0.9.6 before 0.9.6i does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the "Vaudenay timing attack."

The SSL and TLS components for OpenSSL 0.9.6i and earlier, 0.9.7, and 0.9.7a allow remote attackers to perform an unauthorized RSA private key operation via a modified Bleichenbacher attack that uses a large number of SSL or TLS connections using PKCS #1 v1.5 padding that cause OpenSSL to leak information regarding the relationship between ciphertext and the associated plaintext, aka the "Klima-Pokorny-Rosa attack."

OpenSSL does not use RSA blinding by default, which allows local and remote attackers to obtain the server's private key by determining factors using timing differences on (1) the number of extra reductions during Montgomery reduction, and (2) the use of different integer multiplication algorithms ("Karatsuba" and normal).

Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values.

OpenSSL 0.9.6 and 0.9.7 does not properly track the number of characters in certain ASN.1 inputs, which allows remote attackers to cause a denial of service (crash) via an SSL client certificate that causes OpenSSL to read past the end of a buffer when the long form is used.

Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via an SSL client certificate with a certain invalid ASN.1 encoding.

OpenSSL 0.9.6k allows remote attackers to cause a denial of service (crash via large recursion) via malformed ASN.1 sequences.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.

The SSL/TLS handshaking code in OpenSSL 0.9.7a, 0.9.7b, and 0.9.7c, when using Kerberos ciphersuites, does not properly check the length of Kerberos tickets during a handshake, which allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that causes an out-of-bounds read.

The der_chop script in the openssl package in Trustix Secure Linux 1.5 through 2.1 and other operating systems allows local users to overwrite files via a symlink attack on temporary files.

The design of Advanced Encryption Standard (AES), aka Rijndael, allows remote attackers to recover AES keys via timing attacks on S-box lookups, which are difficult to perform in constant time in AES implementations.

The default configuration on OpenSSL before 0.9.8 uses MD5 for creating message digests instead of a more cryptographically strong algorithm, which makes it easier for remote attackers to forge certificates with a valid certificate authority signature.

The SSL/TLS server implementation in OpenSSL 0.9.7 before 0.9.7h and 0.9.8 before 0.9.8a, when using the SSL_OP_MSIE_SSLV2_RSA_PADDING option, disables a verification step that is required for preventing protocol version rollback attacks, which allows remote attackers to force a client and server to use a weaker protocol than needed via a man-in-the-middle attack.

OpenSSL 0.9.7 before 0.9.7l and 0.9.8 before 0.9.8d allows remote attackers to cause a denial of service (infinite loop and memory consumption) via malformed ASN.1 structures that trigger an improperly handled error condition.

OpenSSL 0.9.7 before 0.9.7l, 0.9.8 before 0.9.8d, and earlier versions allows attackers to cause a denial of service (CPU consumption) via parasitic public keys with large (1) "public exponent" or (2) "public modulus" values in X.509 certificates that require extra time to process when using RSA signature verification.