Amazon Linux AMI update for ruby23

1) Security restrictions bypass

EUVDB-ID: #VU8121

Risk: Low

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-7798

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to the openssl gem for Ruby uses the same initialization vector (IV) in GCM Mode (aes-*-gcm) when the IV is set before the key. A remote attacker can bypass the encryption protection mechanism and gain access to the system.

Mitigation

Update the affected packages.

i686:
    ruby23-debuginfo-2.3.4-1.15.amzn1.i686
    ruby23-devel-2.3.4-1.15.amzn1.i686
    rubygem23-psych-2.1.0-1.15.amzn1.i686
    rubygem23-io-console-0.4.5-1.15.amzn1.i686
    ruby23-2.3.4-1.15.amzn1.i686
    rubygem23-bigdecimal-1.2.8-1.15.amzn1.i686
    ruby23-libs-2.3.4-1.15.amzn1.i686

noarch:
    ruby23-doc-2.3.4-1.15.amzn1.noarch
    rubygems23-devel-2.5.2-1.15.amzn1.noarch
    rubygem23-did_you_mean-1.0.0-1.15.amzn1.noarch
    ruby23-irb-2.3.4-1.15.amzn1.noarch
    rubygems23-2.5.2-1.15.amzn1.noarch

src:
    ruby23-2.3.4-1.15.amzn1.src

x86_64:
    ruby23-2.3.4-1.15.amzn1.x86_64
    rubygem23-io-console-0.4.5-1.15.amzn1.x86_64
    ruby23-devel-2.3.4-1.15.amzn1.x86_64
    rubygem23-bigdecimal-1.2.8-1.15.amzn1.x86_64
    ruby23-debuginfo-2.3.4-1.15.amzn1.x86_64
    ruby23-libs-2.3.4-1.15.amzn1.x86_64
    rubygem23-psych-2.1.0-1.15.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2017-880.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.