Summary
StringIO buffer overread vulnerability
An issue was discovered in StringIO 3.0.1, as distributed in Ruby 3.0.x through 3.0.6 and 3.1.x through 3.1.4.
The ungetbyte and ungetc methods on a StringIO can read past the end of a string, and a subsequent call to StringIO.gets may return the memory value.
This vulnerability is not affected StringIO 3.0.3 and later, and Ruby 3.2.x and later.
We recommend to update the StringIO gem to version 3.0.3 or later. In order to ensure compatibility with bundled version in older Ruby series, you may update as follows instead:
- For Ruby 3.0 users: Update to
stringio3.0.1.1 - For Ruby 3.1 users: Update to
stringio3.1.0.2
You can use gem update stringio to update it. If you are using bundler, please add gem "stringio", ">= 3.0.1.2" to your Gemfile.
Impact
CVE-2024-27280 has a CVSS score of 9.8 (Critical). 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 (3.0.1.1); 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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Frequently Asked Questions
- What is CVE-2024-27280? CVE-2024-27280 is a critical-severity security vulnerability in stringio (rubygems), affecting versions < 3.0.1.1. It is fixed in 3.0.1.1.
- How severe is CVE-2024-27280? CVE-2024-27280 has a CVSS score of 9.8 (Critical). 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 stringio are affected by CVE-2024-27280? stringio (rubygems) versions < 3.0.1.1 is affected.
- Is there a fix for CVE-2024-27280? Yes. CVE-2024-27280 is fixed in 3.0.1.1. Upgrade to this version or later.
- Is CVE-2024-27280 exploitable, and should I be worried? Whether CVE-2024-27280 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-2024-27280 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-2024-27280? Upgrade
stringioto 3.0.1.1 or later.