Apple has released iOS 4 for iPhone 3G and later, and iPod touch (2nd generation) and later, to address multiple vulnerabilities across several packages. These vulnerabilities may allow an attacker to execute arbitrary code, cause a denial-of-service condition, disclose sensitive information, bypass security restrictions, or conduct cross-site scripting attacks.
US-CERT encourages users and administrators to review Apple article HT4225 and update to iOS 4 as necessary to help mitigate the risks.