Summary
Untrusted users can run pending migrations in production in Rails
There is a vulnerability in versions of Rails prior to 6.0.3.2 that allowed an untrusted user to run any pending migrations on a Rails app running in production.
This vulnerability has been assigned the CVE identifier CVE-2020-8185.
Versions Affected: 6.0.0 < rails < 6.0.3.2
Not affected: Applications with config.action_dispatch.show_exceptions = false (this is not a default setting in production)
Fixed Versions: rails >= 6.0.3.2
Impact
Using this issue, an attacker would be able to execute any migrations that are pending for a Rails app running in production mode. It is important to note that an attacker is limited to running migrations the application developer has already defined in their application and ones that have not already run.
Workarounds
Until such time as the patch can be applied, application developers should disable the ActionDispatch middleware in their production environment via a line such as this one in their config/environment/production.rb:
config.middleware.delete ActionDispatch::ActionableExceptions
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2020-8185 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low 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 (6.0.3.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
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.
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Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2020-8185? CVE-2020-8185 is a medium-severity uncontrolled resource consumption vulnerability in actionpack (rubygems), affecting versions >= 6.0.0, <= 6.0.3.1. It is fixed in 6.0.3.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2020-8185? CVE-2020-8185 has a CVSS score of 6.5 (Medium). 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.
- Which versions of actionpack are affected by CVE-2020-8185? actionpack (rubygems) versions >= 6.0.0, <= 6.0.3.1 is affected.
- Is there a fix for CVE-2020-8185? Yes. CVE-2020-8185 is fixed in 6.0.3.2. Upgrade to this version or later.
- Is CVE-2020-8185 exploitable, and should I be worried? Whether CVE-2020-8185 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
- What actually determines whether CVE-2020-8185 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.
- How do I fix CVE-2020-8185? Upgrade
actionpackto 6.0.3.2 or later.