PT-2021-15522 · Clearance · Clearance

Mottini Mauro · Published 2021-09-12 · Updated 2021-09-23 · CVE-2021-23435

Positive Technologies (AI Summary)

CVSS v3.1

7.6

High

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

Name of the Vulnerable Software and Affected Versions clearance versions prior to 2.5.0

Description The issue arises when users can set the value of session[:return to]. If the value used for return to contains multiple leading slashes (e.g., /////example.com), the user is redirected to the external domain that comes after the slashes (e.g., http://example.com).

Recommendations For versions prior to 2.5.0, consider updating to version 2.5.0 or later to resolve the issue. As a temporary workaround, restrict the ability of users to set the value of session[:return to] or validate and sanitize the return to value to prevent redirection to external domains.

Exploit

Fix

Open Redirect

Weakness Enumeration

CWE-601

Related Identifiers

CVE-2021-23435

GHSA-4HPQ-RJCX-7VJ9

SNYK-RUBY-CLEARANCE-1577284

Affected Products

Clearance

References · 10

• 🔥 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/clearance/CVE-2021-23435.yml · Exploit
• https://github.com/thoughtbot/clearance/pull/945 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2021-23435 · Security Note
• https://osv.dev/vulnerability/GHSA-4hpq-rjcx-7vj9 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-23435 · Vendor Advisory
• https://github.com/thoughtbot/clearance · Note
• https://github.com/advisories/GHSA-4hpq-rjcx-7vj9 · Note
• https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284 · Note
• https://t.me/cvenotify/20721 · Telegram Post
• https://t.me/cibsecurity/28706 · Telegram Post