CVE-2015-20108: 
Ruby vulnerability analysis and mitigation

CVE-2015-20108 affects the xml_security.rb component in the ruby-saml gem versions prior to 1.0.0. The vulnerability was discovered in 2015 and allows XPath injection and code execution due to the lack of prepared statements (GitHub Commit, NVD).

The vulnerability has been assigned a CVSS v3.1 base score of 9.8 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. The issue stems from improper neutralization of special elements used in a command, classified as CWE-77. The vulnerability specifically affects the handling of XML documents where prepared statements are not used in XPath queries (NVD, NetApp Advisory).

Successful exploitation of this vulnerability could lead to disclosure of sensitive information, addition or modification of data, or Denial of Service (DoS). The critical CVSS score indicates that the vulnerability can result in complete compromise of system confidentiality, integrity, and availability (NetApp Advisory).

The vulnerability is remotely exploitable and requires no privileges or user interaction. The attack complexity is low, making it relatively straightforward to exploit. Public discussion of this vulnerability has been acknowledged by security researchers (NetApp Advisory).

The vulnerability was fixed in ruby-saml version 1.0.0. Users should upgrade to this version or later to address the security issue. The fix involves proper handling of XPath queries using prepared statements (GitHub Commit).