CVE-2024-34075
kurwov vulnerable to Denial of Service due to improper data sanitization
Impact
### 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 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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | kurwov | >= 3.1.0, < 3.2.5 | 3.2.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/xiboon/kurwov/blob/0d58dfa42135ab40e830e92622857282f980ca89/src/MarkovData.ts#L38-L44
- https://github.com/xiboon/kurwov/commit/85d63e652594f121d6656177d7a3c0d823c976c9
- https://github.com/xiboon/kurwov/security/advisories/GHSA-hfrv-h3q8-9jpr
- https://github.com/advisories/GHSA-hfrv-h3q8-9jpr
- https://nvd.nist.gov/vuln/detail/CVE-2024-34075