Description
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 & v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
nodeca js-yaml
>= 3.0.0, < 3.15.2affected>= 4.0.0, < 4.3.2affected>= 5.0.0, < 5.4.1affected
References
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh ↗
- https://github.com/nodeca/js-yaml/pull/797 ↗
- https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639 ↗
- https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480 ↗
- https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b ↗
- https://github.com/nodeca/js-yaml/releases/tag/3.15.2 ↗
- https://github.com/nodeca/js-yaml/releases/tag/4.3.2 ↗
- https://github.com/nodeca/js-yaml/releases/tag/5.4.1 ↗