The FileUtils.remove_entry_secure method in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, 1.8.8dev, 1.9.1 through 1.9.1-430, 1.9.2 through 1.9.2-136, and 1.9.3dev allows local users to delete arbitrary files via a symlink attack.

The safe-level feature in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, and 1.8.8dev allows context-dependent attackers to modify strings via the Exception#to_s method, as demonstrated by changing an intended pathname.

The BigDecimal library in Ruby 1.8.6 before p369 and 1.8.7 before p173 allows context-dependent attackers to cause a denial of service (application crash) via a string argument that represents a large number, as demonstrated by an attempted conversion to the Float data type.

resolv.rb in Ruby 1.8.5 and earlier, 1.8.6 before 1.8.6-p287, 1.8.7 before 1.8.7-p72, and 1.9 r18423 and earlier uses sequential transaction IDs and constant source ports for DNS requests, which makes it easier for remote attackers to spoof DNS responses, a different vulnerability than CVE-2008-1447.

The REXML module in Ruby 1.8.6 through 1.8.6-p287, 1.8.7 through 1.8.7-p72, and 1.9 allows context-dependent attackers to cause a denial of service (CPU consumption) via an XML document with recursively nested entities, aka an "XML entity explosion."

The regular expression engine (regex.c) in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows remote attackers to cause a denial of service (infinite loop and crash) via multiple long requests to a Ruby socket, related to memory allocation failure, and as demonstrated against Webrick.

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.

Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 does not properly restrict access to critical variables and methods at various safe levels, which allows context-dependent attackers to bypass intended access restrictions via (1) untrace_var, (2) $PROGRAM_NAME, and (3) syslog at safe level 4, and (4) insecure methods at safe levels 1 through 3.

The dl module in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 does not check "taintness" of inputs, which allows context-dependent attackers to bypass safe levels and execute dangerous functions by accessing a library using DL.dlopen.