SB2019112701 - Ubuntu update for Ruby
Published: November 27, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Code injection (CVE-ID: CVE-2019-16255)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation in lib/shell.rb in Ruby when processing Shell#[] and its alias Shell#test. A remote attacker can send a specially crafted request and execute arbitrary Ruby code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) HTTP Response Splitting (CVE-ID: CVE-2019-16254)
The vulnerability allows a remote attacker to perform HTTP response splitting attack.
The vulnerability exists due to insufficient validation of CRLF sequences within the WEBrick in Ruby. A remote attacker can send a specially crafted request to the application and perform a spoofing attack.
3) Input validation error (CVE-ID: CVE-2019-16201)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input within the WEBrick::HTTPAuth::DigestAuth in Ruby due to a regular expression issue. A remote attacker can send a specially crafted request to the application and perform a denial of service attack.
4) Input validation error (CVE-ID: CVE-2019-15845)
The vulnerability allows a remote attacker to bypass certain security restrictions.
The vulnerability exists in Ruby due to insufficient validation of user-supplied files within File.fnmatch and File.fnmatch? functions when processing NUL byte in the filename. A remote attacker can bypass implemented security restrictions and gain unauthorized access to the system.
Remediation
Install update from vendor's website.