Circumvention of file size limits in ActiveStorage
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.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2020-8162US | high7.5 | Exploit | ||
A client side enforcement of server side security vulnerability exists in rails < 5.2.4.2 and rails < 6.0.3.1 ActiveStorage's S3 adapter that allows the Content-Length of a direct… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/aws/aws-sdk-rubyWEB
- https://github.com/aws/aws-sdk-ruby/issues/2098WEB
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2020-8162.ymlWEB
- https://groups.google.com/forum/#!topic/rubyonrails-security/PjU3946mreQWEB
- https://groups.google.com/g/rubyonrails-security/c/PjU3946mreQWEB
- https://hackerone.com/reports/789579WEB
- https://nvd.nist.gov/vuln/detail/CVE-2020-8162ADVISORY
- https://www.debian.org/security/2020/dsa-4766WEB
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