Scientific Linux Security Update : openssl on SL5.x i386/x86_64 (Logjam)
Medium Nessus Plugin ID 84542
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionAn out-of-bounds read flaw was found in the X509_cmp_time() function of OpenSSL. A specially crafted X.509 certificate or a Certificate Revocation List (CRL) could possibly cause a TLS/SSL server or client using OpenSSL to crash. (CVE-2015-1789)
A NULL pointer dereference was found in the way OpenSSL handled certain PKCS#7 inputs. A specially crafted PKCS#7 input with missing EncryptedContent data could cause an application using OpenSSL to crash. (CVE-2015-1790)
A flaw was found in the way the TLS protocol composes the Diffie-Hellman (DH) key exchange. A man-in-the-middle attacker could use this flaw to force the use of weak 512 bit export-grade keys during the key exchange, allowing them to decrypt all traffic.
Note: This update forces the TLS/SSL client implementation in OpenSSL to reject DH key sizes below 768 bits, which prevents sessions to be downgraded to export-grade keys. Future updates may raise this limit to 1024 bits.
For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.
SolutionUpdate the affected packages.