CVE-2021-21289 Command Injection Vulnerability in Mechanize

What is CVE-2021-21289?

CVE-2021-21289 is a high-severity vulnerability in Debian Debian Linux, published on 2 Feb 2021.

Official description

Mechanize is an open-source ruby library that makes automated web interaction easy. In Mechanize from version 2.0.0 and before version 2.7.7 there is a command injection vulnerability. Affected versions of mechanize allow for OS commands to be injected using several classes' methods which implicitly use Ruby's Kernel.open method. Exploitation is possible only if untrusted input is used as a local filename and passed to any of these calls: Mechanize::CookieJar#load, Mechanize::CookieJar#save_as, Mechanize#download, Mechanize::Download#save, Mechanize::File#save, and Mechanize::FileResponse#read_body. This is fixed in version 2.7.7.

Weakness: CWE-78

Which versions are affected by CVE-2021-21289?

2 open source packages ship an affected version, including mechanize. It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Mechanize Project Mechanize.

How do I fix CVE-2021-21289?

Upgrade mechanize to 2.7.7 or later.

Is CVE-2021-21289 being exploited?

There is no known exploitation of CVE-2021-21289 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-21289, DLA-2561-1, GHSA-qrqm-fpv6-6r8g, MGASA-2021-0124, UBUNTU-CVE-2021-21289.