CVE-2021-29456: Github.com/authelia/authelia/v4 Authelia Allows Open Redirects On Vulnerability
MODERATECVE-2021-29456 is a MODERATE (CVSS 5.4) authelia allows open redirects on vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Github.com/authelia/authelia/v4 libraries in the Go ecosystem. The issue involves authelia allows open redirects on the logout endpoint. Remediation is available by upgrading affected packages to version 4.28.0.
CVE-2021-29456 at a Glance
Security Impact
CVSS: 5.4
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N).
How to Fix CVE-2021-29456
To remediate this vulnerability, upgrade all affected Github.com/authelia/authelia/v4 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/authelia/authelia/v4 to 4.28.0
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/authelia/authelia/v4
How to Check if You Are Affected
To determine whether your application is affected by CVE-2021-29456, inspect your project dependencies for Github.com/authelia/authelia/v4:
inspect dependencies for github.com/authelia/authelia/v4
Analyze the terminal output to locate any version of Github.com/authelia/authelia/v4 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.28.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect'), where the web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. In Github.com/authelia/authelia/v4, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-29456 Affected Github.com/authelia/authelia/v4 Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/authelia/authelia/v4
|
Go |
< 4.28.0
|
4.28.0
|
References
Frequently Asked Questions
What is CVE-2021-29456?
Which Github.com/authelia/authelia/v4 versions are affected?
What version fixes CVE-2021-29456?
Is github.com/authelia/authelia/v4 affected?
What is the CVSS score of CVE-2021-29456?
What CWE is associated with CVE-2021-29456?
How can I check Go dependencies for CVE-2021-29456?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-36f2-fcrx-fp4j",
"modified" : "2023-03-16T16:04:56Z",
"published" : "2023-03-16T16:04:56Z",
"aliases" : [ "CVE-2021-29456" ],
"summary" : "Authelia allows open redirects on the logout endpoint",
"details" : "### Impact\nUtilizing a HTTP query parameter an attacker is able to redirect users from the web application to any domain. The URL of the intended redirect should always be checked for safety prior to forwarding the user. Other endpoints of the web application already do this, they check both that the domain is using the HTTPS protocol and that it exists on a domain associated with the application.\n\nAn attacker is able to use this unintended functionality to redirect users to malicious sites. This particular security issue allows the attacker to make a phishing attempt seem much more trustworthy to a user of the web application as the initial site before redirection is familiar to them, as well as the actual URL which they have theoretically visited frequently. \n\nWhile this security issue does not directly impact the security of the web application, it is still not an acceptable scenario for the reasons mentioned above. \n\n### Patches\nf0cb75e1e102f95f91e9254c66c797e821857690 fix(handlers): logout redirection validation (#1908) [v4.28.0](https://github.com/authelia/authelia/releases/tag/v4.28.0)\n\n### Workarounds\nUsing a reverse proxy to strip the query parameter from the affected endpoint. \n\n### References\nhttps://github.com/authelia/authelia/pull/1908\n\n[CWE-601](https://cwe.mitre.org/data/definitions/601.html)\n\n[Authelia v4.28.0](https://github.com/authelia/authelia/tree/v4.28.0)\n\n### For more information\nIf you have any questions or comments about this advisory, please [contact us](https://github.com/authelia/authelia#contact-options). You may also contact us to request creating a back-ported fix for this if you are able to explain why you cannot upgrade; however upgrading is highly preferable. ",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/authelia/authelia/v4"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "4.28.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/authelia/authelia/security/advisories/GHSA-36f2-fcrx-fp4j"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-29456"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/authelia/authelia"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-601" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2023-03-16T16:04:56Z",
"nvd_published_at" : "2021-04-21T19:15:00Z"
}
}