Red Hat Security Advisory: rh-ruby25-ruby security, bug fix, and enhancement update

Moderate

A flaw was discovered in Ruby in the way certain functions handled strings containing NULL bytes. Specifically, the built-in methods File.fnmatch and its alias File.fnmatch? did not properly handle path patterns containing the NULL byte. A remote attacker could exploit this flaw to make a Ruby script access unexpected files and to bypass intended file system access restrictions.

CWE-41 - Improper Resolution of Path Equivalence

WEBrick::HTTPAuth::DigestAuth in Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 has a regular expression Denial of Service cause by looping/backtracking. A victim must expose a WEBrick server that uses DigestAuth to the Internet or a untrusted network.

CWE-400 - Uncontrolled Resource Consumption

Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows HTTP Response Splitting. If a program using WEBrick inserts untrusted input into the response header, an attacker can exploit it to insert a newline character to split a header, and inject malicious content to deceive clients. NOTE: this issue exists because of an incomplete fix for CVE-2017-17742, which addressed the CRLF vector, but did not address an isolated CR or an isolated LF.

CWE-113 - Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows code injection if the first argument (aka the "command" argument) to Shell#[] or Shell#test in lib/shell.rb is untrusted data. An attacker can exploit this to call an arbitrary Ruby method.

CWE-94 - Improper Control of Generation of Code ('Code Injection')

A flaw was found in rubygem-json. While parsing certain JSON documents, the json gem (including the one bundled with Ruby) can be coerced into creating arbitrary objects in the target system. This is the same issue as CVE-2013-0269.

CWE-915 - Improperly Controlled Modification of Dynamically-Determined Object Attributes