RHSA-2018:0378 - Security Advisory

Topic

An update for ruby is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

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)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux for ARM 64 7 aarch64
• Red Hat Enterprise Linux for Power 9 7 ppc64le
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1487552 - CVE-2017-14064 ruby: Arbitrary heap exposure during a JSON.generate call
• BZ - 1487587 - CVE-2017-0901 rubygems: Arbitrary file overwrite due to incorrect validation of specification name
• BZ - 1487588 - CVE-2017-0900 rubygems: No size limit in summary length of gem spec
• BZ - 1487589 - CVE-2017-0902 rubygems: DNS hijacking vulnerability
• BZ - 1487590 - CVE-2017-0899 rubygems: Escape sequence in the "summary" field of gemspec
• BZ - 1491866 - CVE-2017-14033 ruby: Buffer underrun in OpenSSL ASN1 decode
• BZ - 1492012 - CVE-2017-10784 ruby: Escape sequence injection vulnerability in the Basic authentication of WEBrick
• BZ - 1492015 - CVE-2017-0898 ruby: Buffer underrun vulnerability in Kernel.sprintf
• BZ - 1500488 - CVE-2017-0903 rubygems: Unsafe object deserialization through YAML formatted gem specifications
• BZ - 1526189 - CVE-2017-17405 ruby: Command injection vulnerability in Net::FTP
• BZ - 1528218 - CVE-2017-17790 ruby: Command injection in lib/resolv.rb:lazy_initialize() allows arbitrary code execution

CVEs

• CVE-2017-0898
• CVE-2017-0899
• CVE-2017-0900
• CVE-2017-0901
• CVE-2017-0902
• CVE-2017-0903
• CVE-2017-10784
• CVE-2017-14033
• CVE-2017-14064
• CVE-2017-17405
• CVE-2017-17790

References

• https://access.redhat.com/security/updates/classification/#important