Threats affecting pkg:npm/apostrophe

ApostropheCMS versions prior to 4.32.1 are vulnerable to a second-order prototype pollution vulnerability via a PATCH request to the article API endpoint. An attacker with a valid editor session can submit a specially crafted payload that overwrites the global toString function, causing a persistent denial-of-service condition in a single request. This vulnerability has a CVSS 4.0 score of 7.1 and is classified as high severity. A fix is available in version 4.32.1.

A stored cross-site scripting (XSS) vulnerability exists in ApostropheCMS versions prior to 4.29.0 in SEO-related fields such as SEO Title and Meta Description. This flaw allows injection of arbitrary JavaScript into HTML contexts including <title>, <meta> attributes, and JSON-LD structured data. Exploitation enables execution of scripts in authenticated admin users' browsers, permitting authenticated API requests and exfiltration of sensitive user data. The vulnerability is patched in version 4.29.0.

ApostropheCMS is an open-source Node.js content management system. A regression introduced in commit 49d0bb7, included in versions 2.17.1 of the ApostropheCMS-maintained sanitize-html package bypasses allowedTags enforcement for text inside nonTextTagsArray elements (textarea and option). ApostropheCMS version 4.28.0 is affected through its dependency on the vulnerable sanitize-html version. The code at packages/sanitize-html/index.js:569-573 incorrectly assumes that htmlparser2 does not decode entities inside these elements and skips escaping, but htmlparser2 10.x does decode entities before passing text to the ontext callback. As a result, entity-encoded HTML is decoded by the parser and then written directly to the output as literal HTML characters, completely bypassing the allowedTags filter. An attacker can inject arbitrary tags including XSS payloads through any allowed option or textarea element using entity encoding. This affects non-default configurations where option or textarea are included in allowedTags, which is common in form builders and CMS platforms. This issue has been fixed in version 2.17.2 of sanitize-html and 4.29.0 of ApostropheCMS.