ruphus13 notes a six-pack of serious vulnerabilities discovered in Ruby by a member of Apple's security team, Drew Yao. Patches are linked from the ruby-lang.org advisory. "With the following vulnerabilities, an attacker can lead to denial of service condition or execute arbitrary code... These vulnerabilities are likely to crop up in just about any average ruby web application. And by 'crop up' I mean 'crop up exploitable from trivial user-specified parameters.' It's not hard to begin imagining cases where Ruby/Rails programmers use code similar to the samples above to routinely handle user input."