Possible XSS Security Vulnerability in SafeBuffer#bytesplice
Moderate severity
GitHub Reviewed
Published
Mar 15, 2023
to the GitHub Advisory Database
•
Updated Mar 15, 2023
Package
Affected versions
>= 7.0.0, < 7.0.4.3
< 6.1.7.3
Patched versions
7.0.4.3
6.1.7.3
Description
Published to the GitHub Advisory Database
Mar 15, 2023
Reviewed
Mar 15, 2023
Last updated
Mar 15, 2023
There is a vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input.
This vulnerability has been assigned the CVE identifier CVE-2023-28120.
Versions Affected: All. Not affected: None Fixed Versions: 7.0.4.3, 6.1.7.3
Impact
ActiveSupport uses the SafeBuffer string subclass to tag strings as html_safe after they have been sanitized.
When these strings are mutated, the tag is should be removed to mark them as no longer being html_safe.
Ruby 3.2 introduced a new bytesplice method which ActiveSupport did not yet understand to be a mutation.
Users on older versions of Ruby are likely unaffected.
All users running an affected release and using bytesplice should either upgrade or use one of the workarounds immediately.
Workarounds
Avoid calling bytesplice on a SafeBuffer (html_safe) string with untrusted user input.
References