CVE-2024-34075 – kurwov

Package

Manager: npm
Name: kurwov
Vulnerable Version: >=3.1.0 <3.2.5

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 6e-05 pctl0.0031

Details

kurwov vulnerable to Denial of Service due to improper data sanitization ### 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.

Metadata

Created: 2024-05-03T20:30:38Z
Modified: 2024-05-03T20:30:38Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/05/GHSA-hfrv-h3q8-9jpr/GHSA-hfrv-h3q8-9jpr.json
CWE IDs: ["CWE-502"]
Alternative ID: GHSA-hfrv-h3q8-9jpr
Finding: F096
Auto approve: 1