Debian DLA-1735-1 : ruby2.1 security update
High Nessus Plugin ID 123522
SynopsisThe remote Debian host is missing a security update.
DescriptionSeveral vulnerabilities have been discovered in rubygems embedded in ruby2.1, the interpreted scripting language.
A Directory Traversal issue was discovered in RubyGems. Before making new directories or touching files (which now include path-checking code for symlinks), it would delete the target destination.
The gem owner command outputs the contents of the API response directly to stdout. Therefore, if the response is crafted, escape sequence injection may occur.
Gem::GemcutterUtilities#with_response may output the API response to stdout as it is. Therefore, if the API side modifies the response, escape sequence injection may occur.
A crafted gem with a multi-line name is not handled correctly.
Therefore, an attacker could inject arbitrary code to the stub line of gemspec, which is eval-ed by code in ensure_loadable_spec during the preinstall check.
An issue was discovered in RubyGems 2.6 and later through 3.0.2. Since Gem::CommandManager#run calls alert_error without escaping, escape sequence injection is possible. (There are many ways to cause an error.)
For Debian 8 'Jessie', these problems have been fixed in version 2.1.5-2+deb8u7.
We recommend that you upgrade your ruby2.1 packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected packages.