CVE-2021-3515 : What You Need to Know

A shell injection vulnerability was discovered in pglogical versions prior to 2.3.4 and 3.6.26. This flaw could be exploited by an attacker with CREATEDB privileges on a PostgreSQL server to execute shell commands as the postgresql user.

Understanding CVE-2021-3515

This section provides insights into the impact, technical details, and mitigation strategies related to CVE-2021-3515.

What is CVE-2021-3515?

The vulnerability in pglogical allows an attacker to execute shell commands by manipulating the database name during a specific function call.

The Impact of CVE-2021-3515

An attacker with certain privileges on the PostgreSQL server can take advantage of this vulnerability to run arbitrary shell commands as the postgresql user, potentially leading to unauthorized access and data manipulation.

Technical Details of CVE-2021-3515

Let's delve into the specifics of how this vulnerability can be described and exploited.

Vulnerability Description

The vulnerability arises from the lack of proper input validation, allowing specially-crafted database names to trigger shell command execution.

Affected Systems and Versions

pglogical versions before 2.3.4 and 3.6.26 are confirmed to be vulnerable to this exploit.

Exploitation Mechanism

By leveraging CREATEDB privileges, an attacker can manipulate the database name when invoking pglogical.create_subscription() to inject and execute arbitrary shell commands.

Mitigation and Prevention

To safeguard systems from potential exploitation, consider the following steps and best practices.

Immediate Steps to Take

Update pglogical to versions 2.3.4 or 3.6.26 to eliminate the vulnerability.
Restrict network access to PostgreSQL servers to trusted entities only.

Long-Term Security Practices

Regularly review and apply security patches to all software components.
Enforce the principle of least privilege to minimize the impact of potential security breaches.

Patching and Updates

Stay informed about security advisories and updates from pglogical and PostgreSQL communities to ensure timely patching and protection against emerging threats.