CVE-2024-34075 is a medium-severity (CVSS 6.2) Deserialization of Untrusted Data vulnerability in kurwov. A fix is available for kurwov — see the affected versions and patch details below.
kurwov vulnerable to Denial of Service due to improper data sanitization
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-34075.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
kurwovnpmDescription
Summary
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
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | kurwov | ≥ 3.1.0&&< 3.2.5 | 3.2.5npm install kurwov@3.2.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for kurwov, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update kurwov to 3.2.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-34075 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.
Frequently Asked Questions
Is CVE-2024-34075 in your dependencies?
Find it across npm, including transitive dependencies.