CVE-2021-43837 : Vulnerability Insights and Analysis

Vault-cli is a command-line interface tool to interact with Hashicorp Vault, featuring templated values rendering vulnerability before version 3.0.0. Users are advised to upgrade immediately or apply workarounds to secure their systems.

Understanding CVE-2021-43837

Vault-cli vulnerability enables Remote Code Execution (RCE) risks through Jinja2 template rendering, impacting confidentiality, integrity, and availability.

What is CVE-2021-43837?

Vault-cli < 3.0.0 interprets Jinja2 templates in secrets, allowing attackers to execute arbitrary code, posing RCE risks.

The Impact of CVE-2021-43837

Attack Vector: ADJACENT_NETWORK
Attack Complexity: LOW
Confidentiality, Integrity, and Availability Impact: HIGH
Privileges Required: HIGH
Vector String: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Technical Details of CVE-2021-43837

CVE-2021-43837 involves template injection through vault-cli rendering. It's crucial to understand the vulnerability, affected systems, and exploitation mechanisms.

Vulnerability Description

Vault-cli pre-3.0.0 renders templated values, allowing attackers to trigger arbitrary code through Jinja2 templates.

Affected Systems and Versions

Product: vault-cli
Vendor: peopledoc
Versions Affected: >= 0.7.0,< 3.0.0

Exploitation Mechanism

If secret values in the vault are manipulated by attackers using vault-cli, RCE risks arise.

Mitigation and Prevention

To safeguard systems from CVE-2021-43837, immediate actions and long-term security practices are essential.

Immediate Steps to Take

Upgrade vault-cli to version 3.0.0 or later.
Apply workarounds: set

VAULT_CLI_RENDER=false

, use

--no-render

flag, or disable rendering in configuration files.

Long-Term Security Practices

Utilize secure configuration settings in vault-cli.
Regularly monitor and update systems to prevent vulnerabilities.

Patching and Updates

Upgrade vault-cli to version 3.0.0 or newer to eliminate the vulnerability.