Answer in brief
CVE-2021-21289 records a High severity (CVSS 7.4) vulnerability in Command Injection Vulnerability in Mechanize. The current sources do not mark it as known exploited. The current feed maps mechanize (rubygems). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps mechanize (rubygems). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| mechanizerubygems | >=2.0.0 <2.7.7 | 2.7.7 |
Published upstream
Feb 2, 2021
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
This security advisory has been created for public disclosure of a Command Injection vulnerability that was responsibly reported by @kyoshidajp (Katsuhiko YOSHIDA). ### Impact Mechanize `>= v2.0`, `< v2.7.7` allows 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`: since v2.0 (see 208e3ed) - `Mechanize::CookieJar#save_as`: since v2.0 (see 5b776a4) - `Mechanize#download`: since v2.2 (see dc91667) - `Mechanize::Download#save` and `#save!` since v2.1 (see 98b2f51, bd62ff0) - `Mechanize::File#save` and `#save_as`: since v2.1 (see 2bf7519) - `Mechanize::FileResponse#read_body`: since v2.0 (see 01039f5) ### Patches These vulnerabilities are patched in Mechanize v2.7.7. ### Workarounds No workarounds are available. We recommend upgrading to v2.7.7 or later. ### References See https://docs.rubocop.org/rubocop/cops_security.html#securityopen for background on why `Kernel.open` should not be used with untrusted input. ### For more information If you have any questions or comments about this advisory, please open an issue in [sparklemotion/mechanize](https://github.com/sparklemotion/mechanize/issues/new).
Quoted source text, attributed separately from HOL analysis.