CVE-2020-16253: 
Ruby vulnerability analysis and mitigation

The PgHero gem through version 2.6.0 for Ruby contains a Cross-Site Request Forgery (CSRF) vulnerability. The vulnerability was discovered on August 4, 2020, and was assigned CVE-2020-16253. This security issue affects the PgHero dashboard in various deployment methods including the Docker image, Linux packages, and in specific cases, the Ruby gem implementation (PgHero Issue).

The vulnerability stems from PgHero's use of the protect_from_forgery method from Rails with a default setting of :null_session, which proves ineffective for non-session based authentication methods. The issue specifically affects implementations using non-session based authentication methods like basic authentication, while session-based authentication methods such as Devise's default authentication remain unaffected. The vulnerability has been assigned a CVSS v3.1 base score of 8.1 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H (NVD).

The vulnerability allows attackers to perform unauthorized actions through CSRF attacks when an authorized user visits a malicious website. The potential unauthorized actions include canceling running queries, executing EXPLAIN commands on queries (which can be used for denial of service attacks), and resetting query statistics through pg_stat_statements_reset() (PgHero Issue).

The vulnerability can be exploited by tricking an authenticated user into visiting a malicious website, which can then perform unauthorized requests on behalf of the user. The attack specifically targets implementations using non-session based authentication methods (PgHero Issue).

The vulnerability has been fixed in version 2.7.0 by changing the protect_from_forgery setting to use :exception instead of :null_session. All users running affected versions (2.6.0 and below) are advised to upgrade immediately to version 2.7.0 or later (PgHero Issue).