CVE-2021-21337: Products.PluggableAuthService URL Redirection To Untrusted Site Vulnerability
MODERATECVE-2021-21337 is a MODERATE (CVSS 5.7) url redirection to untrusted site vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Products.PluggableAuthService libraries in the PyPI ecosystem. The issue involves url redirection to untrusted site ('open redirect') in products.pluggableauthservice. Remediation is available by upgrading affected packages to version 2.6.1.
CVE-2021-21337 at a Glance
Security Impact
CVSS: 5.7
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:U/C:H/I:N/A:N).
How to Fix CVE-2021-21337
To remediate this vulnerability, upgrade all affected Products.PluggableAuthService dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
pip install Products.PluggableAuthService>=2.6.1Run the following command in your project directory to verify that all resolved dependencies use the patched release:
pip show Products.PluggableAuthServiceHow to Check if You Are Affected
To determine whether your Python environment is affected by CVE-2021-21337, inspect your installed packages using pip:
pip show Products.PluggableAuthServiceAnalyze the terminal output to locate any version of Products.PluggableAuthService in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.6.1), your application is affected.
Note: The pip show Products.PluggableAuthService command checks currently installed packages in your active Python environment.
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 Products.PluggableAuthService, 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-2021-21337 Affected Products.PluggableAuthService Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
Products.PluggableAuthService
|
PyPI |
< 2.6.1
|
2.6.1
|
References
Frequently Asked Questions
What is CVE-2021-21337?
Which Products.PluggableAuthService versions are affected?
What version fixes CVE-2021-21337?
Is Products.PluggableAuthService affected?
What is the CVSS score of CVE-2021-21337?
What CWE is associated with CVE-2021-21337?
How can I check PyPI dependencies for CVE-2021-21337?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-p44j-xrqg-4xrr",
"modified" : "2024-10-21T19:59:54Z",
"published" : "2021-03-08T21:06:23Z",
"aliases" : [ "CVE-2021-21337" ],
"summary" : "URL Redirection to Untrusted Site ('Open Redirect') in Products.PluggableAuthService",
"details" : "### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nOpen redirect vulnerability - a maliciously crafted link to the login form and login functionality could redirect the browser to a different website.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\nThe problem has been fixed in version 2.6.1. Depending on how you have installed Products.PluggableAuthService, you should change the buildout version pin to `2.6.1` and re-run the buildout, or if you used `pip` simply do `pip install \"Products.PluggableAuthService>=2.6.1\"`\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nThere is no workaround. Users are encouraged to upgrade.\n\n### References\n_Are there any links users can visit to find out more?_\n\n- [GHSA-p44j-xrqg-4xrr](https://github.com/zopefoundation/Products.PluggableAuthService/security/advisories/GHSA-p44j-xrqg-4xrr)\n- [Products.PluggableAuthService on PyPI](https://pypi.org/project/Products.PluggableAuthService/)\n- [OWASP page on open redirects](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [Products.PluggableAuthService issue tracker](https://github.com/zopefoundation/Products.PluggableAuthService/issues)\n* Email us at [security@plone.org](mailto:security@plone.org)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N"
}, {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "PyPI",
"name" : "Products.PluggableAuthService"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "2.6.1"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/zopefoundation/Products.PluggableAuthService/security/advisories/GHSA-p44j-xrqg-4xrr"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21337"
}, {
"type" : "WEB",
"url" : "https://github.com/zopefoundation/Products.PluggableAuthService/commit/7eead067898852ebd3e0f143bc51295928528dfa"
}, {
"type" : "WEB",
"url" : "https://github.com/pypa/advisory-database/tree/main/vulns/products-pluggableauthservice/PYSEC-2021-45.yaml"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/zopefoundation/Products.PluggableAuthService"
}, {
"type" : "WEB",
"url" : "https://pypi.org/project/Products.PluggableAuthService"
}, {
"type" : "WEB",
"url" : "http://packetstormsecurity.com/files/162911/Products.PluggableAuthService-2.6.0-Open-Redirect.html"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-601" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2021-03-08T21:06:09Z",
"nvd_published_at" : "2021-03-08T21:15:00Z"
}
}