CVE-2019-10010
Moderate severity vulnerability that affects league/commonmark
描述
## CVE-2019-10010 ### Impact In `league/commonmark` 0.18.2 and below, malicious users can insert double-encoded HTML entities into their Markdown like this: ```md [XSS](javascript&colon;alert%28'XSS'%29) ``` This library would (correctly) unescape the `&` entity to `&` during the parsing step. However, **the renderer step would fail to properly re-escape the resulting `:` string**, thus producing the following malicious HTML output: ```html <p><a href="javascript:alert('XSS')">XSS</a></p> ``` Browsers would interpret `:` as a `:` character and allow the JS to be executed when the link is clicked. This vulnerability was present in the upstream library this project was forked from and therefore exists in all prior versions of `league/commonmark`. ### Solution The new [0.18.3](https://github.com/thephpleague/commonmark/releases/tag/0.18.3) release mirrors [the fix made upstream](https://github.com/commonmark/commonmark.js/commit/c89b35c5fc99bdf1d2181f7f0c9fcb8a1abc27c8) - we no longer attempt to preserve entities when rendering HTML attributes like `href`, `src`, `title`, etc. The `$preserveEntities` parameter of `Xml::escape()` is therefore no longer used internally, so it has been deprecated and marked for removal in the next major release (0.19.0). ### Credits - Mohit Fawaz for identifying the issue - Sebastiaan Knijnenburg and Ross Tuck for responsibly disclosing/relaying the issue - John MacFarlane for investigating it and implementing the upstream fix we mirrored here ### References - https://nvd.nist.gov/vuln/detail/CVE-2019-10010 - https://github.com/thephpleague/commonmark/releases/tag/0.18.3 - https://github.com/thephpleague/commonmark/issues/353 - https://github.com/FriendsOfPHP/security-advisories/blob/master/league/commonmark/CVE-2019-10010.yaml
如何修補 CVE-2019-10010
要修補 CVE-2019-10010,請將受影響套件升級到下列已修補版本。
- —升級至 0.18.3 或更新版本
CVE-2019-10010 正在被利用嗎?
低 — EPSS 為 1.1%,目前沒有觀察到大規模利用活動。