Amazon Linux AMI Security Advisory: ALAS-2018-1065
Advisory Release Date: 2018-08-22 18:59 Pacific
Advisory Updated Date: 2018-08-23 17:31 Pacific
Because of an implementation bug the PA-RISC CRYPTO_memcmp function is effectively reduced to only comparing the least significant bit of each byte. This allows an attacker to forge messages that would be considered as authenticated in an amount of tries lower than that guaranteed by the security claims of the scheme. The module can only be compiled by the HP-UX assembler, so that only HP-UX PA-RISC targets are affected.(CVE-2018-0733)
Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack given malicious input with excessive recursion. This could result in a Denial Of Service attack. There are no such structures used within SSL/TLS that come from untrusted sources so this is considered safe.(CVE-2018-0739)
Run yum update openssl to update your system.