Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.4%
exploitation probability
0.4%top 62% of all CVEs
observed exploitation
nono source reports it
Browserslist is a configuration tool for sharing target browsers and Node.js versions between front-end tools. Prior to 4.28.7, normalizeStats() in node.js, reached unconditionally through getStat() and loadStat() on every browserslist() call, processes untrusted browserslist-stats.json, opts.stats, and CLI --stats data with an unguarded for...in loop and plain-object bracket access and assignment, allowing inherited Object.prototype keys including __proto__, toString, valueOf, constructor, hasOwnProperty, and isPrototypeOf to cause an uncaught TypeError or modify the prototype of the returned normalized object. This issue is fixed in version 4.28.7.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
browserslist · browserslist