Bug 1980648 (CVE-2021-3639) - CVE-2021-3639 mod_auth_mellon: Open Redirect vulnerability in logout URLs
Summary: CVE-2021-3639 mod_auth_mellon: Open Redirect vulnerability in logout URLs
Alias: CVE-2021-3639
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1986805 1986806 1986807 1988235
Blocks: 1978058
TreeView+ depends on / blocked
Reported: 2021-07-09 06:39 UTC by Dhananjay Arunesh
Modified: 2022-05-11 18:16 UTC (History)
9 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in mod_auth_mellon where it does not sanitize logout URLs properly. This issue could be used by an attacker to facilitate phishing attacks by tricking users into visiting a trusted web application URL that redirects to an external and potentially malicious server. The highest threat from this liability is to confidentiality and integrity.
Clone Of:
Last Closed: 2022-05-11 18:16:08 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2022:1934 0 None None None 2022-05-10 14:22:50 UTC

Description Dhananjay Arunesh 2021-07-09 06:39:06 UTC
A vulnerability was found in mod_auth_mellon where it does not sanatize logout  URLs properly results in phishing attacks by tricking users.

Comment 4 Riccardo Schirone 2021-07-28 11:30:47 UTC
The vulnerability is in auth_mellon_util.c:am_check_url() function, where there are not enough checks to ensure the redirect URL is fine. An attacker may provide a logout URL, starting with "///", of an application that uses mod_auth_mellon to a victim user, so that he is redirected to another site. The user may pay less attention to the URL as the application that uses mod_auth_mellon may be trusted.

Comment 6 Riccardo Schirone 2021-07-30 05:47:54 UTC
Created mod_auth_mellon tracking bugs for this issue:

Affects: fedora-all [bug 1988235]

Comment 7 errata-xmlrpc 2022-05-10 14:22:47 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1934 https://access.redhat.com/errata/RHSA-2022:1934

Comment 8 Product Security DevOps Team 2022-05-11 18:16:06 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


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