ESB-2018.0314 - [Ubuntu] Ruby: Multiple vulnerabilities 2018-02-01

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             AUSCERT External Security Bulletin Redistribution

                           Ruby vulnerabilities
                              1 February 2018


        AusCERT Security Bulletin Summary

Product:           Ruby
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Execute Arbitrary Code/Commands -- Remote with User Interaction
                   Overwrite Arbitrary Files       -- Remote with User Interaction
                   Provide Misleading Information  -- Remote with User Interaction
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-0903 CVE-2017-0902 CVE-2017-0901

Reference:         ASB-2017.0137

Original Bulletin:

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USN-3553-1: Ruby vulnerabilities
Ubuntu Security Notice USN-3553-1

31st January, 2018

ruby2.3 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

    Ubuntu 17.10
    Ubuntu 16.04 LTS


Several security issues were fixed in Ruby.
Software description

    ruby2.3 - Interpreter of object-oriented scripting language Ruby


It was discovered that Ruby failed to validate specification names.
An attacker could possibly use a maliciously crafted gem to potentially
overwrite any file on the filesystem. (CVE-2017-0901)

It was discovered that Ruby was vulnerable to a DNS hijacking vulnerability.
An attacker could use this to possibly force the RubyGems client to download
and install gems from a server that the attacker controls. (CVE-2017-0902)

It was discovered that Ruby incorrectly handled certain YAML files. An attacker
could use this to possibly execute arbitrary code. (CVE-2017-0903)

Update instructions

The problem can be corrected by updating your system to the following package

Ubuntu 17.10:
    libruby2.3 2.3.3-1ubuntu1.3
    ruby2.3 2.3.3-1ubuntu1.3
Ubuntu 16.04 LTS:
    libruby2.3 2.3.1-2~16.04.6
    ruby2.3 2.3.1-2~16.04.6

To update your system, please follow these instructions:

In general, a standard system update will make all the necessary changes.


CVE-2017-0901, CVE-2017-0902, CVE-2017-0903

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