GHSA-FX3V-553X-3C4Q
Vulnerability from github – Published: 2020-11-23 19:47 – Updated: 2021-03-04 18:24Impact
Backend users with access to upload files were permitted to upload SVG files without any sanitization applied to the uploaded files. Since SVG files support being parsed as HTML by browsers, this means that they could theoretically upload Javascript that would be executed on a path under the website's domain (i.e. /storage/app/media/evil.svg), but they would have to convince their target to visit that location directly in the target's browser as the backend does not display SVGs inline anywhere, SVGs are only displayed as image resources in the backend and are thus unable to be executed.
Patches
Issue has been patched in Build 469 (v1.0.469) & v1.1.0.
Workarounds
Apply https://github.com/octobercms/library/commit/80aab47f044a2660aa352450f55137598f362aa4 to your installation manually if unable to upgrade to Build 469 or v1.1.0.
References
Reported by Hoan Hoang
For more information
If you have any questions or comments about this advisory: * Email us at hello@octobercms.com
Threat assessment:

{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "october/backend"
},
"ranges": [
{
"events": [
{
"introduced": "1.0.319"
},
{
"fixed": "1.0.469"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-15249"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2020-11-23T19:47:07Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Impact\nBackend users with access to upload files were permitted to upload SVG files without any sanitization applied to the uploaded files. Since SVG files support being parsed as HTML by browsers, this means that they could theoretically upload Javascript that would be executed on a path under the website\u0027s domain (i.e. /storage/app/media/evil.svg), but they would have to convince their target to visit that location directly in the target\u0027s browser as the backend does not display SVGs inline anywhere, SVGs are only displayed as image resources in the backend and are thus unable to be executed.\n\n### Patches\nIssue has been patched in Build 469 (v1.0.469) \u0026 v1.1.0.\n\n### Workarounds\nApply https://github.com/octobercms/library/commit/80aab47f044a2660aa352450f55137598f362aa4 to your installation manually if unable to upgrade to Build 469 or v1.1.0.\n\n### References\nReported by [Hoan Hoang](https://github.com/hoanhp)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [hello@octobercms.com](mailto:hello@octobercms.com)\n\n### Threat assessment:\n\u003cimg width=\"1107\" alt=\"Screen Shot 2020-10-10 at 1 47 49 PM\" src=\"https://user-images.githubusercontent.com/7253840/95663787-378f2b80-0aff-11eb-8dfc-b97d162939da.png\"\u003e",
"id": "GHSA-fx3v-553x-3c4q",
"modified": "2021-03-04T18:24:54Z",
"published": "2020-11-23T19:47:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/octobercms/october/security/advisories/GHSA-fx3v-553x-3c4q"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-15249"
},
{
"type": "WEB",
"url": "https://github.com/octobercms/library/commit/80aab47f044a2660aa352450f55137598f362aa4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Stored XSS by authenticated backend user with access to upload files"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.