A toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Rich support for multibyte strings, internationalization, time zones, and testing.
In ActiveSupport, there is potentially unexpected behaviour in the MemCacheStore and RedisCacheStore where, when
untrusted user input is written to the cache store using the raw: true parameter, re-reading the result
from the cache can evaluate the user input as a Marshalled object instead of plain text. Vulnerable code looks like:
data = cache.fetch("demo", raw: true) { untrusted_string }
Versions Affected: rails < 5.2.5, rails < 6.0.4
Not affected: Applications not using MemCacheStore or RedisCacheStore. Applications that do not use the raw option when storing untrusted user input.
Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1
Impact
Unmarshalling of untrusted user input can have impact up to and including RCE. At a minimum,
this vulnerability allows an attacker to inject untrusted Ruby objects into a web application.
In addition to upgrading to the latest versions of Rails, developers should ensure that whenever
they are calling Rails.cache.fetch they are using consistent values of the raw parameter for both
reading and writing, especially in the case of the RedisCacheStore which does not, prior to these changes,
detect if data was serialized using the raw option upon deserialization.
Workarounds
It is recommended that application developers apply the suggested patch or upgrade to the latest release as
soon as possible. If this is not possible, we recommend ensuring that all user-provided strings cached using
the raw argument should be double-checked to ensure that they conform to the expected format.
There is a possible file disclosure of locally encrypted files in Active Support. This vulnerability has been assigned the CVE identifier CVE-2023-38037.
ActiveSupport::EncryptedFile writes contents that will be encrypted to a temporary file. The temporary file’s permissions are defaulted to the user’s current umask settings, meaning that it’s possible for other users on the same system to read the contents of the temporary file.
Attackers that have access to the file system could possibly read the contents of this temporary file while a user is editing it.
All users running an affected release should either upgrade or use one of the workarounds immediately.
Releases
The fixed releases are available at the normal locations.
Workarounds
To work around this issue, you can set your umask to be more restrictive like this:
There is a possible regular expression based DoS vulnerability in Active Support. This vulnerability has been assigned the CVE identifier CVE-2023-22796.
Versions Affected: All Not affected: None Fixed Versions: 5.2.8.15 (Rails LTS, which is a paid service and not part of the rubygem), 6.1.7.1, 7.0.4.1
Impact
A specially crafted string passed to the underscore method can cause the regular expression engine to enter a state of catastrophic backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability.
This affects String#underscore, ActiveSupport::Inflector.underscore, String#titleize, and any other methods using these.
All users running an affected release should either upgrade or use one of the workarounds immediately.
Releases
The FIXED releases are available at the normal locations.
Workarounds
There are no feasible workarounds for this issue.
Users on Ruby 3.2.0 or greater may be able to reduce the impact by configuring Regexp.timeout.
Patches
To aid users who aren’t able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
6-1-Avoid-regex-backtracking-in-Inflector.underscore.patch - Patch for 6.1 series
7-0-Avoid-regex-backtracking-in-Inflector.underscore.patch - Patch for 7.0 series
Please note that only the 7.0.Z and 6.1.Z series are supported at present, and 6.0.Z for severe vulnerabilities. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases.
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 htmlsafe after they have been sanitized.
When these strings are mutated, the tag is should be removed to mark them as no longer being htmlsafe.
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.
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 htmlsafe after they have been sanitized.
When these strings are mutated, the tag is should be removed to mark them as no longer being htmlsafe.
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.
There is a possible file disclosure of locally encrypted files in Active Support. This vulnerability has been assigned the CVE identifier CVE-2023-38037.
ActiveSupport::EncryptedFile writes contents that will be encrypted to a temporary file. The temporary file’s permissions are defaulted to the user’s current umask settings, meaning that it’s possible for other users on the same system to read the contents of the temporary file.
Attackers that have access to the file system could possibly read the contents of this temporary file while a user is editing it.
All users running an affected release should either upgrade or use one of the workarounds immediately.
Releases
The fixed releases are available at the normal locations.
Workarounds
To work around this issue, you can set your umask to be more restrictive like this:
