🚨 [security] Update rack: 2.0.4 → 2.0.9.1 (minor)

[depfu]

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🚨 Your current dependencies have known security vulnerabilities 🚨

This dependency update fixes known security vulnerabilities. Please see the details below and assess their impact carefully. We recommend to merge and deploy this as soon as possible!

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Here is everything you need to know about this update. Please take a good look at what changed and the test results before merging this pull request.

What changed?

↗️ rack (indirect, 2.0.4 → 2.0.9.1) · Repo · Changelog

Security Advisories 🚨

🚨 Denial of Service Vulnerability in Rack Multipart Parsing

There is a possible denial of service vulnerability in the multipart parsing
component of Rack. This vulnerability has been assigned the CVE identifier
CVE-2022-30122.

Versions Affected: >= 1.2
Not affected: < 1.2
Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1

Impact

Carefully crafted multipart POST requests can cause Rack's multipart parser to
take much longer than expected, leading to a possible denial of service
vulnerability.

Impacted code will use Rack's multipart parser to parse multipart posts. This
includes directly using the multipart parser like this:

params = Rack::Multipart.parse_multipart(env)

But it also includes reading POST data from a Rack request object like this:

p request.POST # read POST data
p request.params # reads both query params and POST data

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Workarounds

There are no feasible workarounds for this issue.

🚨 Possible shell escape sequence injection vulnerability in Rack

There is a possible shell escape sequence injection vulnerability in the Lint
and CommonLogger components of Rack. This vulnerability has been assigned the
CVE identifier CVE-2022-30123.

Versions Affected: All.
Not affected: None
Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1

Impact

Carefully crafted requests can cause shell escape sequences to be written to
the terminal via Rack's Lint middleware and CommonLogger middleware. These
escape sequences can be leveraged to possibly execute commands in the victim's
terminal.

Impacted applications will have either of these middleware installed, and
vulnerable apps may have something like this:

use Rack::Lint

Or

use Rack::CommonLogger

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Workarounds

Remove these middleware from your application

🚨 Possible information leak / session hijack vulnerability

There's a possible information leak / session hijack vulnerability in Rack.

Attackers may be able to find and hijack sessions by using timing attacks
targeting the session id. Session ids are usually stored and indexed in a
database that uses some kind of scheme for speeding up lookups of that
session id. By carefully measuring the amount of time it takes to look up
a session, an attacker may be able to find a valid session id and hijack
the session.

The session id itself may be generated randomly, but the way the session is
indexed by the backing store does not use a secure comparison.

Impact:

The session id stored in a cookie is the same id that is used when querying
the backing session storage engine. Most storage mechanisms (for example a
database) use some sort of indexing in order to speed up the lookup of that
id. By carefully timing requests and session lookup failures, an attacker
may be able to perform a timing attack to determine an existing session id
and hijack that session.

🚨 Possible XSS vulnerability in Rack

There is a possible vulnerability in Rack. This vulnerability has been
assigned the CVE identifier CVE-2018-16471.

Versions Affected: All.
Not affected: None.
Fixed Versions: 2.0.6, 1.6.11

Impact

There is a possible XSS vulnerability in Rack. Carefully crafted requests can
impact the data returned by the scheme method on Rack::Request.
Applications that expect the scheme to be limited to "http" or "https" and do
not escape the return value could be vulnerable to an XSS attack.

Vulnerable code looks something like this:

<%= request.scheme.html_safe %>

Note that applications using the normal escaping mechanisms provided by Rails
may not impacted, but applications that bypass the escaping mechanisms, or do
not use them may be vulnerable.

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Releases

The 2.0.6 and 1.6.11 releases are available at the normal locations.

Workarounds

The following monkey patch can be applied to work around this issue:

require "rack"
require "rack/request"
class Rack::Request

SCHEME_WHITELIST = %w(https http).freeze
def scheme

if get_header(Rack::HTTPS) == 'on'

'https'

elsif get_header(HTTP_X_FORWARDED_SSL) == 'on'

'https'

elsif forwarded_scheme

forwarded_scheme

else

get_header(Rack::RACK_URL_SCHEME)

end

end
def forwarded_scheme

scheme_headers = [

get_header(HTTP_X_FORWARDED_SCHEME),

get_header(HTTP_X_FORWARDED_PROTO).to_s.split(',')[0]

]
scheme_headers.each do |header|

return header if SCHEME_WHITELIST.include?(header)

end
nil

end

end

🚨 Possible DoS vulnerability in Rack

There is a possible DoS vulnerability in the multipart parser in Rack. This
vulnerability has been assigned the CVE identifier CVE-2018-16470.

Versions Affected: 2.0.4, 2.0.5
Not affected: <= 2.0.3
Fixed Versions: 2.0.6

Impact

There is a possible DoS vulnerability in the multipart parser in Rack.
Carefully crafted requests can cause the multipart parser to enter a
pathological state, causing the parser to use CPU resources disproportionate to
the request size.

Impacted code can look something like this:

Rack::Request.new(env).params

But any code that uses the multi-part parser may be vulnerable.

Rack users that have manually adjusted the buffer size in the multipart parser
may be vulnerable as well.

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Releases

The 2.0.6 release is available at the normal locations.

Workarounds

To work around this issue, the following code can be used:

require "rack/multipart/parser"
Rack::Multipart::Parser.send :remove_const, :BUFSIZE

Rack::Multipart::Parser.const_set :BUFSIZE, 16384

Release Notes

2.0.8 (from changelog)

• [CVE-2019-16782] Prevent timing attacks targeted at session ID lookup. (@tenderlove, @rafaelfranca)

Does any of this look wrong? Please let us know.

Commits

See the full diff on Github. The new version differs by 37 commits:

• update changelog
• bump version
• Escape untrusted text when logging
• Restrict broken mime parsing
• bump version
• Handle case where session id key is requested but it is missing
• Merge pull request #1455 from trainline-eu/2-0-stable
• Merge pull request #1462 from jeremyevans/sessionid-to_s
• Added support for SameSite=None cookie value, added in revision 3 of rfc6265bis
• Bumping version
• Introduce a new base class to avoid breaking when upgrading
• Add a version prefix to the private id to make easier to migrate old values
• Fallback to the public id when reading the session in the pool adapter
• Also drop the session with the public id when destroying sessions
• Fallback to the legacy id when the new id is not found
• Add the private id
• revert conditionals to master
• remove NullSession
• remove || raise and get closer to master
• store hashed id, send public id
• use session id objects
• remove more nils
• try to ensure we always have some kind of object
• Bumping to 2.0.7 for release
• Merge pull request #1343 from larsxschneider/ls/forward-fix
• Preserve forwarded IP address for trusted proxy chains
• Merge pull request #1201 from janko-m/make-multipart-parsing-work-for-chunked-requests
• Bumping version for release
• Whitelist http/https schemes
• Reduce buffer size to avoid pathological parsing
• Merge tag '2.0.5' into 2-0-stable
• Merge pull request #1296 from tomelm/fix-prefers-plaintext
• Bump version for release
• Merge pull request #1268 from eileencodes/forwardport-pr-1249-to-2-0-stable
• Merge pull request #1249 from mclark/handle-invalid-method-parameters
• Stick with a passing version of Rubygems and bundler
• Leahize

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