Ecosyste.ms: Advisories

Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLW00MngtMzdwMy1mdjV3

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.

Permalink: https://github.com/advisories/GHSA-m42x-37p3-fv5w
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLW00MngtMzdwMy1mdjV3
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: over 4 years ago
Updated: over 1 year ago

CVSS Score: 7.5
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Percentage: 0.00095
EPSS Percentile: 0.41534

Identifiers: GHSA-m42x-37p3-fv5w, CVE-2020-8162
References:

• 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://hackerone.com/reports/789579
• https://groups.google.com/g/rubyonrails-security/c/PjU3946mreQ
• https://www.debian.org/security/2020/dsa-4766
• https://github.com/aws/aws-sdk-ruby/issues/2098
• https://github.com/advisories/GHSA-m42x-37p3-fv5w

Repository: https://github.com/aws/aws-sdk-ruby
Blast Radius: 41.0

Affected Packages