Summary
URI gem has ReDoS vulnerability
A ReDoS issue was discovered in the URI component before 0.12.2 for Ruby. The URI parser mishandles invalid URLs that have specific characters. There is an increase in execution time for parsing strings to URI objects with rfc2396_parser.rb and rfc3986_parser.rb.
NOTE: this issue exists becuse of an incomplete fix for CVE-2023-28755. Version 0.10.3 is also a fixed version.
The Ruby advisory recommends updating the uri gem to 0.12.2. In order to ensure compatibility with the bundled version in older Ruby series, you may update as follows instead:
- For Ruby 3.0: Update to uri 0.10.3
- For Ruby 3.1 and 3.2: Update to uri 0.12.2.
You can use gem update uri to update it. If you are using bundler, please add gem uri, >= 0.12.2 (or other version mentioned above) to your Gemfile.
Impact
A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.
CVE-2023-36617 has a CVSS score of 5.3 (Medium). 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 (0.10.3, 0.12.2, 0.11.2, 0.10.0.3); 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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See it in your environmentNew to Kodem? Get a demo →Remediation advice
uri to 0.10.3 or later; uri to 0.12.2 or later; uri to 0.11.2 or later; uri to 0.10.0.3 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-36617? CVE-2023-36617 is a medium-severity inefficient regular expression (ReDoS) vulnerability in uri (rubygems), affecting versions >= 0.10.1, < 0.10.3. It is fixed in 0.10.3, 0.12.2, 0.11.2, 0.10.0.3. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
- How severe is CVE-2023-36617? CVE-2023-36617 has a CVSS score of 5.3 (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 uri are affected by CVE-2023-36617? uri (rubygems) versions >= 0.10.1, < 0.10.3 is affected.
- Is there a fix for CVE-2023-36617? Yes. CVE-2023-36617 is fixed in 0.10.3, 0.12.2, 0.11.2, 0.10.0.3. Upgrade to this version or later.
- Is CVE-2023-36617 exploitable, and should I be worried? Whether CVE-2023-36617 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-2023-36617 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-2023-36617?
- Upgrade
urito 0.10.3 or later - Upgrade
urito 0.12.2 or later - Upgrade
urito 0.11.2 or later - Upgrade
urito 0.10.0.3 or later
- Upgrade