CVE-2020-8162
Circumvention of file size limits in ActiveStorage
Impact
There is a vulnerability in ActiveStorage's S3 adapter that allows the Content-Length of a direct file upload to be modified by an end user. Versions Affected: rails < 5.2.4.2, rails < 6.0.3.1 Not affected: Applications that do not use the direct upload functionality of the ActiveStorage S3 adapter. Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1 Impact ------ Utilizing this vulnerability, an attacker can control the Content-Length of an S3 direct upload URL without receiving a new signature from the server. This could be used to bypass controls in place on the server to limit upload size. Workarounds ----------- This is a low-severity security issue. As such, no workaround is necessarily until such time as the application can be upgraded.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | activestorage | >= 5.0.0, <= 5.2.4.2 | 5.2.4.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Rubyonrails | Rails | before 5.2.4.2 from 6.0.0 before 6.0.3.1 |
| Debian | Debian Linux | Version 10.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://groups.google.com/g/rubyonrails-security/c/PjU3946mreQ
- https://hackerone.com/reports/789579
- https://www.debian.org/security/2020/dsa-4766
- https://github.com/advisories/GHSA-m42x-37p3-fv5w
- https://nvd.nist.gov/vuln/detail/CVE-2020-8162
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2020-8162.yml
- https://groups.google.com/forum/#!topic/rubyonrails-security/PjU3946mreQ
- https://github.com/aws/aws-sdk-ruby/issues/2098