# CVE-2021-21289: Command Injection Vulnerability in Mechanize

Source: https://junglewise.ai/threats/cve-2021-21289-command-injection-vulnerability-in-mechanize  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-02-02  
License: CC BY 4.0 with a link back

CVE-2021-21289 · Severity: low · CVSS 3.1 · Published 2021-02-02

Command Injection Vulnerability in Mechanize

Technologies: [mechanize (RubyGems)](https://junglewise.ai/threats/technologies/rubygems-mechanize). Vendors: [RubyGems](https://junglewise.ai/threats/vendors/rubygems).

## Quick answers

**Is CVE-2021-21289 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-21289 being exploited in the wild.

**How severe is CVE-2021-21289?** Low severity, with a CVSS score of 3.1, published 2 February 2021.

**Which products and versions are affected?** mechanize (RubyGems) ECOSYSTEM:introduced=2.0.0,fixed=2.7.7.

**Is there a fix for CVE-2021-21289?** Yes. mechanize (RubyGems): upgrade to 2.7.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-21289?** Check whether you run mechanize (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- mechanize (RubyGems): upgrade to 2.7.7 or later

  ```sh
  bundle update mechanize
  ```


## Affected products

- mechanize (RubyGems) ECOSYSTEM:introduced=2.0.0,fixed=2.7.7

## Identifiers

- CVE-2021-21289
- GHSA-qrqm-fpv6-6r8g

## Related threats

- [Mechanize HTTP credential leakage via redirect](https://junglewise.ai/threats/cve-2026-107715-mechanize-sends-credential-headers-to-another-host-after-an-http)
- [Mechanize credential leak via meta refresh redirect](https://junglewise.ai/threats/cve-2026-107399-mechanize-sends-credential-headers-to-another-origin-after-a)
- [Mechanize before v2.8.5 vulnerable to authorization header leak on port redirect](https://junglewise.ai/threats/cve-2022-31033-mechanize-before-v2-8-5-vulnerable-to-authorization-header-leak)