OpenSSL 1.0.2 < 1.0.2b Multiple Vulnerabilities (Logjam)
Medium Nessus Plugin ID 84154
SynopsisThe remote service is affected by multiple vulnerabilities.
DescriptionAccording to its banner, the remote web server uses a version of OpenSSL 1.0.2 prior to 1.0.2b. The OpenSSL library is, therefore, affected by the following vulnerabilities :
- A denial of service vulnerability exists when processing an ECParameters structure due to an infinite loop that occurs when a specified curve is over a malformed binary polynomial field. A remote attacker can exploit this to perform a denial of service against any system that processes public keys, certificate requests, or certificates. This includes TLS clients and TLS servers with client authentication enabled. (CVE-2015-1788)
- A denial of service vulnerability exists due to improper validation of the content and length of the ASN1_TIME string by the X509_cmp_time() function. A remote attacker can exploit this, via a malformed certificate and CRLs of various sizes, to cause a segmentation fault, resulting in a denial of service condition. TLS clients that verify CRLs are affected.
TLS clients and servers with client authentication enabled may be affected if they use custom verification callbacks. (CVE-2015-1789)
- A NULL pointer dereference flaw exists in the PKCS#7 parsing code due to incorrect handling of missing inner 'EncryptedContent'. This allows a remote attacker, via specially crafted ASN.1-encoded PKCS#7 blobs with missing content, to cause a denial of service condition or other potential unspecified impacts. (CVE-2015-1790)
- A double-free error exists due to a race condition that occurs when a NewSessionTicket is received by a multi-threaded client when attempting to reuse a previous ticket. (CVE-2015-1791)
- A denial of service vulnerability exists in the CMS code due to an infinite loop that occurs when verifying a signedData message. A remote attacker can exploit this to cause a denial of service condition. (CVE-2015-1792)
- A man-in-the-middle vulnerability, known as Logjam, exists due to a flaw in the SSL/TLS protocol. A remote attacker can exploit this flaw to downgrade connections using ephemeral Diffie-Hellman key exchange to 512-bit export-grade cryptography. (CVE-2015-4000)
SolutionUpgrade to OpenSSL 1.0.2b or later.