FreeBSD : ruby -- Hash-flooding DoS vulnerability for ruby 1.9 (5e647ca3-2aea-11e2-b745-001fd0af1a4c)
Medium Nessus Plugin ID 62886
SynopsisThe remote FreeBSD host is missing a security-related update.
DescriptionThe official ruby site reports :
Carefully crafted sequence of strings can cause a denial of service attack on the service that parses the sequence to create a Hash object by using the strings as keys. For instance, this vulnerability affects web application that parses the JSON data sent from untrusted entity.
This vulnerability is similar to CVS-2011-4815 for ruby 1.8.7. ruby 1.9 versions were using modified MurmurHash function but it's reported that there is a way to create sequence of strings that collide their hash values each other. This fix changes the Hash function of String object from the MurmurHash to SipHash 2-4.
SolutionUpdate the affected package.