[RHSA-2018:0378] ruby security update

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• It was discovered that the Net::FTP module did not properly process filenames in combination with certain operations. A remote attacker could exploit this flaw to execute arbitrary commands by setting up a malicious FTP server and tricking a user or Ruby application into downloading files with specially crafted names using the Net::FTP module. (CVE-2017-17405)

• A buffer underflow was found in ruby's sprintf function. An attacker, with ability to control its format string parameter, could send a specially crafted string that would disclose heap memory or crash the interpreter. (CVE-2017-0898)

• It was found that rubygems did not sanitize gem names during installation of a given gem. A specially crafted gem could use this flaw to install files outside of the regular directory. (CVE-2017-0901)

• A vulnerability was found where rubygems did not sanitize DNS responses when requesting the hostname of the rubygems server for a domain, via a _rubygems._tcp DNS SRV query. An attacker with the ability to manipulate DNS responses could direct the gem command towards a different domain. (CVE-2017-0902)

• A vulnerability was found where the rubygems module was vulnerable to an unsafe YAML deserialization when inspecting a gem. Applications inspecting gem files without installing them can be tricked to execute arbitrary code in the context of the ruby interpreter. (CVE-2017-0903)

• It was found that WEBrick did not sanitize all its log messages. If logs were printed in a terminal, an attacker could interact with the terminal via the use of escape sequences. (CVE-2017-10784)

• It was found that the decode method of the OpenSSL::ASN1 module was vulnerable to buffer underrun. An attacker could pass a specially crafted string to the application in order to crash the ruby interpreter, causing a denial of service. (CVE-2017-14033)

• A vulnerability was found where rubygems did not properly sanitize gems' specification text. A specially crafted gem could interact with the terminal via the use of escape sequences. (CVE-2017-0899)

• It was found that rubygems could use an excessive amount of CPU while parsing a sufficiently long gem summary. A specially crafted gem from a gem repository could freeze gem commands attempting to parse its summary. (CVE-2017-0900)

• A buffer overflow vulnerability was found in the JSON extension of ruby. An attacker with the ability to pass a specially crafted JSON input to the extension could use this flaw to expose the interpreter's heap memory. (CVE-2017-14064)

• The "lazy_initialize" function in lib/resolv.rb did not properly process certain filenames. A remote attacker could possibly exploit this flaw to inject and execute arbitrary commands. (CVE-2017-17790)