Impact
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 octobercms/library@80aab47 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:
Threat assessment:
### References
- https://github.com/octobercms/october/security/advisories/
GHSA-fx3v-553x-3c4q
- https://github.com/octobercms/library/commit/80aab47f044a2660aa352450f55137598f362aa4
- https://nvd.nist.gov/vuln/detail/
CVE-2020-15249
Impact
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 octobercms/library@80aab47 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:
Threat assessment:
### References - https://github.com/octobercms/october/security/advisories/GHSA-fx3v-553x-3c4q - https://github.com/octobercms/library/commit/80aab47f044a2660aa352450f55137598f362aa4 - https://nvd.nist.gov/vuln/detail/CVE-2020-15249