CVE-2021-28680

CVE-2021-28680 is a high-severity improper privilege management vulnerability in devise_masquerade (rubygems), affecting versions < 1.3.1. It is fixed in 1.3.1.

Does this CVE actually affect you?

Kodem shows which CVEs are reachable and running in your applications, so you fix what's exploitable, not just what's listed.

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Runtime intelligence, not another scanner.

Summary

Improper Privilege Management in devise_masquerade

The devise_masquerade gem before 1.3 allows certain attacks when a password's salt is unknown. An application that uses this gem to let administrators masquerade/impersonate users loses one layer of security protection compared to a situation where Devise (without this extension) is used. If the server-side secret_key_base value became publicly known (for instance if it is committed to a public repository by mistake), there are still other protections in place that prevent an attacker from impersonating any user on the site. When masquerading is not used in a plain Devise application, one must know the password salt of the target user if one wants to encrypt and sign a valid session cookie. When devise_masquerade is used, however, an attacker can decide which user the "back" action will go back to without knowing that user's password salt and simply knowing the user ID, by manipulating the session cookie and pretending that a user is already masqueraded by an administrator.

Impact

The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access. Typical impact: privilege escalation beyond the intended level.

CVE-2021-28680 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.3.1); upgrading removes the vulnerable code path.

Affected versions

devise_masquerade (< 1.3.1)

Security releases

devise_masquerade → 1.3.1 (rubygems)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

Already deployed Kodem?

See it in your environmentNew to Kodem? Get a demo →

Remediation advice

Upgrade devise_masquerade to 1.3.1 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

  1. What is CVE-2021-28680? CVE-2021-28680 is a high-severity improper privilege management vulnerability in devise_masquerade (rubygems), affecting versions < 1.3.1. It is fixed in 1.3.1. The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access.
  2. How severe is CVE-2021-28680? CVE-2021-28680 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
  3. Which versions of devise_masquerade are affected by CVE-2021-28680? devise_masquerade (rubygems) versions < 1.3.1 is affected.
  4. Is there a fix for CVE-2021-28680? Yes. CVE-2021-28680 is fixed in 1.3.1. Upgrade to this version or later.
  5. Is CVE-2021-28680 exploitable, and should I be worried? Whether CVE-2021-28680 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
  6. What actually determines whether CVE-2021-28680 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
  7. How do I fix CVE-2021-28680? Upgrade devise_masquerade to 1.3.1 or later.

Stop the waste.
Protect your environment with Kodem.