CVE-2024-34075

CVE-2024-34075 is a medium-severity insecure deserialization vulnerability in kurwov (npm), affecting versions >= 3.1.0, < 3.2.5. It is fixed in 3.2.5.

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Summary

kurwov vulnerable to Denial of Service due to improper data sanitization

An unsafe sanitization of dataset contents on the MarkovData#getNext method used in Markov#generate and Markov#choose allows a maliciously crafted string on the dataset to throw and stop the function from running properly.

Details

https://github.com/xiboon/kurwov/blob/0d58dfa42135ab40e830e92622857282f980ca89/src/MarkovData.ts#L38-L44

If a string contains a forbidden substring (i.e. __proto__) followed by a space character, the second line will access a special property in MarkovData#finalData by removing the last character of the string, bypassing the dataset sanitization (as it is supposed to be already sanitized before this function is called).

data is then defined as the special function found in its prototype instead of an array.

On the last line, data is then indexed by a random number, which is supposed to return a string but returns undefined as it's a function. Calling endsWith then throws.

PoC

https://runkit.com/embed/m6uu40r5ja9b

Impact

Any dataset can be contaminated with the substring making it unable to properly generate anything in some cases.

Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.

CVE-2024-34075 has a CVSS score of 6.2 (Medium). The vector is requires local access, 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 (3.2.5); upgrading removes the vulnerable code path.

Affected versions

kurwov (>= 3.1.0, < 3.2.5)

Security releases

kurwov → 3.2.5 (npm)

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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Remediation advice

Upgrade kurwov to 3.2.5 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-2024-34075? CVE-2024-34075 is a medium-severity insecure deserialization vulnerability in kurwov (npm), affecting versions >= 3.1.0, < 3.2.5. It is fixed in 3.2.5. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
  2. How severe is CVE-2024-34075? CVE-2024-34075 has a CVSS score of 6.2 (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.
  3. Which versions of kurwov are affected by CVE-2024-34075? kurwov (npm) versions >= 3.1.0, < 3.2.5 is affected.
  4. Is there a fix for CVE-2024-34075? Yes. CVE-2024-34075 is fixed in 3.2.5. Upgrade to this version or later.
  5. Is CVE-2024-34075 exploitable, and should I be worried? Whether CVE-2024-34075 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-2024-34075 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-2024-34075? Upgrade kurwov to 3.2.5 or later.

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