CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
Percentile
61.0%
There is a possible Open Redirect Vulnerability in Action Pack. This
vulnerability has been assigned the CVE identifier CVE-2021-22903.
Versions Affected: >= v6.1.0.rc2
Not affected: < v6.1.0.rc2
Fixed Versions: 6.1.3.2
This is similar to CVE-2021-22881: Specially crafted Host headers in
combination with certain “allowed host” formats can cause the Host
Authorization middleware in Action Pack to redirect users to a malicious
website.
Since rails/rails@9bc7ea5, strings in config.hosts that do not have a leading
dot are converted to regular expressions without proper escaping. This causes,
for example, config.hosts << “sub.example.com” to permit a request with a Host
header value of sub-example.com.
The following monkey patch put in an initializer can be used as a workaround:
class ActionDispatch::HostAuthorization::Permissions
def sanitize_string(host)
if host.start_with?(".")
/\A(.+\.)?#{Regexp.escape(host[1..-1])}\z/i
else
/\A#{Regexp.escape host}\z/i
end
end
end
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
Percentile
61.0%