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CVE-2017-0899: Rubygems: Improper Neutralization of Escape, Meta, or Control Sequences

CVE-2017-0899 is rated critical with a CVSS v3.0 base score of 9.8 and affects Rubygems, along with 7 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

RubyGems version 2.6.12 and earlier is vulnerable to maliciously crafted gem specifications that include terminal escape characters. Printing the gem specification would execute terminal escape sequences.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.

CWE-94: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

Affected products

Rubygems: up to and including 2.6.12
Debian Linux: 8.0; 9.0
Red Hat Enterprise Linux Desktop: 7.0
Red Hat Enterprise Linux Server: 7.0
Red Hat Enterprise Linux Server Aus: 7.4; 7.6
Red Hat Enterprise Linux Server Eus: 7.4; 7.5; 7.6
Red Hat Enterprise Linux Server Tus: 7.4; 7.6
Red Hat Enterprise Linux Workstation: 7.0