New! Vulnerability Priority Rating (VPR)
Tenable calculates a dynamic VPR for every vulnerability. VPR combines vulnerability information with threat intelligence and machine learning algorithms to predict which vulnerabilities are most likely to be exploited in attacks. Read more about what VPR is and how it's different from CVSS.
VPR Score: 6.7
Synopsis
The remote service is affected by multiple vulnerabilities.
Description
According to its banner, the remote host is running a version of OpenSSL 1.0.1 prior to 1.0.1u. It is, therefore, affected by the following vulnerabilities :
- Multiple integer overflow conditions exist in s3_srvr.c, ssl_sess.c, and t1_lib.c due to improper use of pointer arithmetic for heap-buffer boundary checks. An unauthenticated, remote attacker can exploit this to cause a denial of service. (CVE-2016-2177)
- An information disclosure vulnerability exists in the dsa_sign_setup() function in dsa_ossl.c due to a failure to properly ensure the use of constant-time operations.
An unauthenticated, remote attacker can exploit this, via a timing side-channel attack, to disclose DSA key information. (CVE-2016-2178)
- A denial of service vulnerability exists in the DTLS implementation due to a failure to properly restrict the lifetime of queue entries associated with unused out-of-order messages. An unauthenticated, remote attacker can exploit this, by maintaining multiple crafted DTLS sessions simultaneously, to exhaust memory.
(CVE-2016-2179)
- An out-of-bounds read error exists in the X.509 Public Key Infrastructure Time-Stamp Protocol (TSP) implementation. An unauthenticated, remote attacker can exploit this, via a crafted time-stamp file that is mishandled by the 'openssl ts' command, to cause denial of service or to disclose sensitive information.
(CVE-2016-2180)
- A denial of service vulnerability exists in the Anti-Replay feature in the DTLS implementation due to improper handling of epoch sequence numbers in records.
An unauthenticated, remote attacker can exploit this, via spoofed DTLS records, to cause legitimate packets to be dropped. (CVE-2016-2181)
- An overflow condition exists in the BN_bn2dec() function in bn_print.c due to improper validation of user-supplied input when handling BIGNUM values. An unauthenticated, remote attacker can exploit this to crash the process. (CVE-2016-2182)
- A vulnerability exists, known as SWEET32, in the 3DES and Blowfish algorithms due to the use of weak 64-bit block ciphers by default. A man-in-the-middle attacker who has sufficient resources can exploit this vulnerability, via a 'birthday' attack, to detect a collision that leaks the XOR between the fixed secret and a known plaintext, allowing the disclosure of the secret text, such as secure HTTPS cookies, and possibly resulting in the hijacking of an authenticated session.
(CVE-2016-2183)
- A flaw exists in the tls_decrypt_ticket() function in t1_lib.c due to improper handling of ticket HMAC digests. An unauthenticated, remote attacker can exploit this, via a ticket that is too short, to crash the process, resulting in a denial of service.
(CVE-2016-6302)
- An integer overflow condition exists in the MDC2_Update() function in mdc2dgst.c due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this to cause a heap-based buffer overflow, resulting in a denial of service condition or possibly the execution of arbitrary code.
(CVE-2016-6303)
- A flaw exists in the ssl_parse_clienthello_tlsext() function in t1_lib.c due to improper handling of overly large OCSP Status Request extensions from clients. An unauthenticated, remote attacker can exploit this, via large OCSP Status Request extensions, to exhaust memory resources, resulting in a denial of service condition.
(CVE-2016-6304)
- An out-of-bounds read error exists in the certificate parser that allows an unauthenticated, remote attacker to cause a denial of service via crafted certificate operations. (CVE-2016-6306)
- A flaw exists in the GOST ciphersuites due to the use of long-term keys to establish an encrypted connection. A man-in-the-middle attacker can exploit this, via a Key Compromise Impersonation (KCI) attack, to impersonate the server.
Solution
Upgrade to OpenSSL version 1.0.1u or later.
Note that the GOST ciphersuites vulnerability is not yet fixed by the vendor in an official release; however, a patch for the issue has been committed to the OpenSSL github repository.