Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2021-32618— Open Redirect Vulnerability

Quick assessment

Affected
Flask-Middleware flask-security
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

flask-security是一个应用软件。快速向Flask应用程序添加安全功能。 Flask-Security-Too 存在输入验证错误漏洞，攻击者可以使用合法站点将此类链接发送给不知情的用户，然后将其重定向到他们想要的任何站点。

CVSS 3.1 · Low EPSS 3.29% · P88

Public Exploits 1

Nuclei · 1 CVE-2021-32618.yaml [template]
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-32618

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Open Redirect Vulnerability
Source: CVE Program / CVE List V5
Vulnerability Description
The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and 'fill in the blanks' when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\github.com will pass FS's relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the 'autocorrect_location_header=False`.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
指向未可信站点的URL重定向(开放重定向)
Source: CVE Program / CVE List V5
Vulnerability Title
flask-security 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
flask-security是一个应用软件。快速向Flask应用程序添加安全功能。 Flask-Security-Too 存在输入验证错误漏洞，攻击者可以使用合法站点将此类链接发送给不知情的用户，然后将其重定向到他们想要的任何站点。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Flask-Middleware flask-security <= 4.0.1 -

II. Public POCs for CVE-2021-32618

# POC Description Source Link Shenlong Link
1 Python Flask-Security contains an open redirect vulnerability. Existing code validates that the URL specified in the next parameter is either relative or has the same network location as the requesting URL. Certain browsers accept and fill in the blanks of possibly incomplete or malformed URLs. An attacker can redirect a user to a malicious site and possibly obtain sensitive information, modify data, and/or execute unauthorized operations. https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-32618.yaml POC Details
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-32618

请登录查看更多情报信息。

Vendor Advisories for CVE-2021-32618 (1)

Other References for CVE-2021-32618 (1)

IV. Related Vulnerabilities

Same product: flask-security
Same vendor: Flask-Middleware
Same weakness: CWE-601

V. Comments for CVE-2021-32618

No comments yet

Leave a comment