Overview
CVE-2006-4112 describes an unspecified vulnerability in Rails 1.1.0 through 1.1.5 where the dependency resolution and routing logic can be abused by crafted URLs to execute arbitrary Ruby code. This could cause denial of service (application hang) or data loss and is noted as distinct from CVE-2006-4111. In real-world scenarios, such issues arise when routing code improperly evaluates or resolves parts of a URL, granting an attacker the ability to trigger unsafe code paths. The vulnerability effectively undermines function-level access controls by exploiting the routing layer to reach code paths that should be off-limits. Patch coverage was released to address these routing/dependency resolution weaknesses.
Affected Versions
1.1.0-1.1.5
Code Fix Example
Ruby on Rails API Security Remediation
Vulnerable (illustrative, non-operational pattern):
# Vulnerable (illustrative) pattern: dynamic controller resolution from user input
class Router
def self.route(path)
controller_name, action = path.split('/')[0,2]
# Dangerous: constructing a constant from user-supplied input
controller_class = Object.const_get("#{controller_name.capitalize}Controller")
controller_class.new.send(action)
end
end
# Fixed: explicit whitelist and Rails routing best practices
ALLOWED_CONTROLLERS = %w[UsersController SessionsController ProductsController]
class Router
def self.route(path)
controller_name, action = path.split('/')[0,2]
controller_class_name = "#{controller_name.capitalize}Controller"
unless ALLOWED_CONTROLLERS.include?(controller_class_name)
raise "Not Found"
end
controller_class = Object.const_get(controller_class_name)
# Use a safe call instead of arbitrary dynamic dispatch
controller_class.new.public_send(action)
end
end