Security restrictions bypass in Ruby - CVE-2018-16396

Vulnerability identifier: #VU15725

CSH Severity: Low

CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2018-16396

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The weakness exists due to the tainted flags are not propagated with the B, b, H, and h directives. A remote attacker can supply inputs by Array#pack and/or String#unpack with these directives and checks the reliability with tainted flags and cause the check to be wrong to bypass security restrictions and conduct further attacks.

Ruby
Amazon Linux AMI
Debian Linux
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM System z (Structure A)
Red Hat Enterprise Linux for Power 9
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux EUS Compute Node
Red Hat Enterprise Linux for Power, big endian - Extended Update Support
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Opensuse
Fedora
EMC Integrated Data Protection Appliance
ruby (Red Hat package)
ruby (Alpine package)
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
ruby
Dell EMC Data Protection Search

The vulnerability has been fixed in the versions 2.3.8, 2.4.5, 2.5.2.

Ruby - addressed in versions 2.3.8, 2.4.5, 2.5.2
EMC Integrated Data Protection Appliance - update to 2.7.1
ruby (Red Hat package) - addressed in versions 2.0.0.648-37.el7_4, 2.0.0.648-38.el7_6
ruby (Alpine package) - update to 2.3.8-r0
Dell EMC Data Protection Search - update to 19.6.0
ruby - addressed in versions 2.4.5-90.fc27, 2.5.3-94.fc28, 2.5.3-99.fc29

• https://www.ruby-lang.org/en/news/2018/10/17/not-propagated-taint-flag-in-some-formats-of-pack-cve-2018-16396/

• Debian update for ruby2.3
• Red Hat update for ruby
• Red Hat update for ruby
• Red Hat update for ruby
• Amazon Linux AMI update for ruby23
• Red Hat update for ruby
• OpenSUSE Linux update for ruby-bundled-gems-rpmhelper, ruby2.5
• Red Hat Enterprise Linux 7 update for ruby
• Red Hat Enterprise Linux 7 update for ruby
• Amazon Linux AMI update for ruby20
• Security restrictions bypass in ruby (Alpine package)
• Multiple vulnerabilities in Dell EMC Integrated Data Protection Appliance
• Multiple vulnerabilities in Dell EMC Data Protection Search
• Fedora 29 update for ruby
• Fedora 28 update for ruby
• Fedora 27 update for ruby