Blog
05 Mar 2019
March 2019 Security Advisories
by Hiroshi SHIBATA
Today we’re disclosing several vulnerablities to RubyGems. They have all been reported via hackerone.
We strongly recommend to upgrade the latest stable version of RubyGems 3.0.3 or 2.7.8. If you can’t upgrade RubyGems 2.7 or 3.0, please use this patch for RubyGems 2.6.
CVE-2019-8320: Delete directory using symlink when decompressing tar
Description
A Directory Traversal issue was discovered in RubyGems 2.7.6 and later through 3.0.2.
Before making new directories or touching files (which now include
path-checking code for symlinks), it would delete the target
destination. If that destination was hidden behind a symlink, a
malicious gem could delete arbitrary files on the user’s machine,
presuming the attacker could guess at paths. Given how frequently gem is run
as sudo, and how predictable paths are on modern systems (/tmp,
/usr, etc.), this could likely lead to data loss or an unusable
system.
Reporter
ooooooo_q
CVE-2019-8321: Escape sequence injection vulnerability in verbose
Description
An issue was discovered in RubyGems 2.6 and later through 3.0.2.
Since Gem::UserInteraction#verbose calls say without escaping, escape
sequence injection is possible.
Reporter
ooooooo_q
CVE-2019-8322: Escape sequence injection vulnerability in gem owner
Description
An issue was discovered in RubyGems 2.6 and later through 3.0.2.
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.
Reporter
ooooooo_q
CVE-2019-8323: Escape sequence injection vulnerability in API response handling
Description
An issue was discovered in RubyGems 2.6 and later through 3.0.2.
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.
Reporter
ooooooo_q
CVE-2019-8324: Installing a malicious gem may lead to arbitrary code execution
Description
An issue was discovered in RubyGems 2.6 and later through 3.0.2.
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.
Reporter
nyangawa of Chaitin Tech
CVE-2019-8325: Escape sequence injection vulnerability in errors
Description
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.)
Reporter
ooooooo_q