The package integrity validation in yarn < 1.19.0 contains a TOCTOU vulnerability where the hash is computed before writing a package to cache. It's not computed again when reading from the cache. This may lead to a cache pollution attack. This issue is fixed in 1.19.0.
{ "nvd_published_at": "2020-03-15T18:15:00Z", "severity": "MODERATE", "github_reviewed_at": "2021-04-08T22:21:40Z", "github_reviewed": true, "cwe_ids": [ "CWE-367" ] }