9.3 - DSA-4031

Several vulnerabilities have been discovered in the interpreter for the Ruby language. The Common Vulnerabilities and Exposures project identifies the following problems:

CVE-2017-0898

aerodudrizzt reported a buffer underrun vulnerability in the sprintf method of the Kernel module resulting in heap memory corruption or information disclosure from the heap.

CVE-2017-0903

Max Justicz reported that RubyGems is prone to an unsafe object deserialization vulnerability. When parsed by an application which processes gems, a specially crafted YAML formatted gem specification can lead to remote code execution.

CVE-2017-10784

Yusuke Endoh discovered an escape sequence injection vulnerability in the Basic authentication of WEBrick. An attacker can take advantage of this flaw to inject malicious escape sequences to the WEBrick log and potentially execute control characters on the victim's terminal emulator when reading logs.

CVE-2017-14033

asac reported a buffer underrun vulnerability in the OpenSSL extension. A remote attacker can take advantage of this flaw to cause the Ruby interpreter to crash leading to a denial of service.

For the stable distribution (stretch), these problems have been fixed in version 2.3.3-1+deb9u2.

We recommend that you upgrade your ruby2.3 packages.