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Ubuntu Security Notice USN-3685-2
March 25, 2021

ruby2.0 regression
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 ESM

Summary:

USN-3685-1 introduced a regression in Ruby.

Software Description:
- ruby2.0: Object-oriented scripting language

Details:

USN-3685-1 fixed a vulnerability in Ruby. The fix for CVE-2017-0903 introduced
a regression in Ruby. This update fixes the problem.

Original advisory details:

Some of these CVE were already addressed in previous
USN: 3439-1, 3553-1, 3528-1. Here we address for
the remain releases.

It was discovered that Ruby incorrectly handled certain inputs.
An attacker could use this to cause a buffer overrun. (CVE-2017-0898)

It was discovered that Ruby incorrectly handled certain files.
An attacker could use this to 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)

It was discovered that Ruby incorrectly handled certain files.
An attacker could use this to expose sensitive information.
(CVE-2017-14064)

It was discovered that Ruby incorrectly handled certain inputs.
An attacker could use this to execute arbitrary code. (CVE-2017-10784)

It was discovered that Ruby incorrectly handled certain network requests.
An attacker could possibly use this to inject a crafted key into a HTTP
response. (CVE-2017-17742)

It was discovered that Ruby incorrectly handled certain files.
An attacker could possibly use this to execute arbitrary code.
This update is only addressed to ruby2.0. (CVE-2018-1000074)

It was discovered that Ruby incorrectly handled certain network requests.
An attacker could possibly use this to cause a denial of service.
(CVE-2018-8777)

Update instructions:

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

Ubuntu 14.04 ESM:
  libruby2.0                      2.0.0.484-1ubuntu2.13+esm1
  ruby2.0                         2.0.0.484-1ubuntu2.13+esm1

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

References:
  https://ubuntu.com/security/notices/USN-3685-2
  https://ubuntu.com/security/notices/USN-3685-1
  CVE-2017-0903, https://bugs.launchpad.net/ubuntu/+source/ruby2.0/+bug/1777174