Cisco NX-OS OpenSSL Multiple Vulnerabilities (cisco-sa-20150310-ssl) (FREAK)
Medium Nessus Plugin ID 83528
Synopsis
The remote device is missing a vendor-supplied security patch.
Description
The remote Cisco device is running a version of NX-OS software that is affected by multiple vulnerabilities in its bundled OpenSSL library:
- A NULL pointer dereference flaw exists when the SSLv3 option isn't enabled and an SSLv3 ClientHello is received. This allows a remote attacker, using an unexpected handshake, to crash the daemon, resulting in a denial of service. (CVE-2014-3569)
- The BIGNUM squaring (BN_sqr) implementation does not properly calculate the square of a BIGNUM value. This allows remote attackers to defeat cryptographic protection mechanisms. (CVE-2014-3570)
- A NULL pointer dereference flaw exists with dtls1_get_record() when handling DTLS messages. A remote attacker, using a specially crafted DTLS message, can cause a denial of service. (CVE-2014-3571)
- A flaw exists with ECDH handshakes when using an ECDSA certificate without a ServerKeyExchange message. This allows a remote attacker to trigger a loss of forward secrecy from the ciphersuite. (CVE-2014-3572)
- A flaw exists when accepting non-DER variations of certificate signature algorithms and signature encodings due to a lack of enforcement of matches between signed and unsigned portions. A remote attacker, by including crafted data within a certificate's unsigned portion, can bypass fingerprint-based certificate-blacklist protection mechanisms. (CVE-2014-8275)
- A security feature bypass vulnerability, known as FREAK (Factoring attack on RSA-EXPORT Keys), exists due to the support of weak EXPORT_RSA cipher suites with keys less than or equal to 512 bits. A man-in-the-middle attacker may be able to downgrade the SSL/TLS connection to use EXPORT_RSA cipher suites which can be factored in a short amount of time, allowing the attacker to intercept and decrypt the traffic. (CVE-2015-0204)
- A flaw exists when accepting DH certificates for client authentication without the CertificateVerify message.
This allows a remote attacker to authenticate to the service without a private key. (CVE-2015-0205)
- A memory leak occurs in dtls1_buffer_record() when handling a saturation of DTLS records containing the same number sequence but for the next epoch. This allows a remote attacker to cause a denial of service.
(CVE-2015-0206)
Solution
Apply the patch or workaround supplied by the vendor.