Multiple vulnerabilities were discovered in the interpreter for the Ruby language:
CVE-2015-9096
SMTP command injection in Net::SMTP.
CVE-2016-7798
Incorrect handling of initialization vector in the GCM mode in the OpenSSL extension.
CVE-2017-0900
Denial of service in the RubyGems client.
CVE-2017-0901
Potential file overwrite in the RubyGems client.
CVE-2017-0902
DNS hijacking in the RubyGems client.
CVE-2017-14064
Heap memory disclosure in the JSON library.
For the stable distribution (stretch), these problems have been fixed in version 2.3.3-1+deb9u1. This update also hardens RubyGems against malicious termonal escape sequences (CVE-2017-0899).
We recommend that you upgrade your ruby2.3 packages.
Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/