An issue was discovered in Django 5.2 before 5.2.17 and 6.0 before 6.0.8. django.contrib.admin.utils.displayforfield() renders URLField values as clickable links in the admin without validating the URL. A value stored with an unsafe scheme is displayed as a link on changelist and read-only admin pages, which allows cross-site scripting against staff users who click the link. Exploitation requires the unsafe value to already be stored in the database. URLField validation through a ModelForm or the admin rejects unsafe schemes, so this affects applications that persist URLField data without running model validation, for example through direct queryset writes, deserialization, or bulk import of untrusted input. Django would like to thank Egor Saltykov for reporting this issue.

An issue was discovered in Django 5.1 before 5.1.8 and 5.0 before 5.0.14. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.views.LoginView, django.contrib.auth.views.LogoutView, and django.views.i18n.setlanguage are subject to a potential denial-of-service attack via certain inputs with a very large number of Unicode characters.

An issue was discovered in Django 3.2 before 3.2.23, 4.1 before 4.1.13, and 4.2 before 4.2.7. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.forms.UsernameField is subject to a potential DoS (denial of service) attack via certain inputs with a very large number of Unicode characters.

A flaw was found in django. MultiPartParser, UploadedFile, and FieldFile allowed directory-traversal via uploaded files with suitably crafted file names.

In Django 2.2 before 2.2.22, 3.1 before 3.1.10, and 3.2 before 3.2.2 (with Python 3.9.5+), URLValidator does not prohibit newlines and tabs (unless the URLField form field is used). If an application uses values with newlines in an HTTP response, header injection can occur. Django itself is unaffected because HttpResponse prohibits newlines in HTTP headers.

Django 2.1 before 2.1.15 and 2.2 before 2.2.8 allows unintended model editing. A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. (To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.)

The (1) contrib.sessions.backends.base.SessionBase.flush and (2) cachedb.SessionStore.flush functions in Django 1.7.x before 1.7.10, 1.4.x before 1.4.22, and possibly other versions create empty sessions in certain circumstances, which allows remote attackers to cause a denial of service (session store consumption) via unspecified vectors.

ModelMultipleChoiceField in Django 1.6.x before 1.6.10 and 1.7.x before 1.7.3, when showhiddeninitial is set to True, allows remote attackers to cause a denial of service by submitting duplicate values, which triggers a large number of SQL queries.

The django.util.http.issafeurl function in Django before 1.4.18, 1.6.x before 1.6.10, and 1.7.x before 1.7.3 does not properly handle leading whitespaces, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a crafted URL, related to redirect URLs, as demonstrated by a \njavascript: URL.

The django.views.static.serve view in Django before 1.4.18, 1.6.x before 1.6.10, and 1.7.x before 1.7.3 reads files an entire line at a time, which allows remote attackers to cause a denial of service (memory consumption) via a long line in a file.

Cross-site scripting (XSS) vulnerability in the AdminURLFieldWidget widget in contrib/admin/widgets.py in Django 1.5.x before 1.5.2 and 1.6.x before 1.6 beta 2 allows remote attackers to inject arbitrary web script or HTML via a URLField.

The administrative interface for Django 1.3.x before 1.3.6, 1.4.x before 1.4.4, and 1.5 before release candidate 2 does not check permissions for the history view, which allows remote authenticated administrators to obtain sensitive object history information.

The form library in Django 1.3.x before 1.3.6, 1.4.x before 1.4.4, and 1.5 before release candidate 2 allows remote attackers to bypass intended resource limits for formsets and cause a denial of service (memory consumption) or trigger server errors via a modified maxnum parameter.

An issue was discovered in Django 2.1 before 2.1.2, in which unprivileged users can read the password hashes of arbitrary accounts. The read-only password widget used by the Django Admin to display an obfuscated password hash was bypassed if a user has only the "view" permission (new in Django 2.1), resulting in display of the entire password hash to those users. This may result in a vulnerability for sites with legacy user accounts using insecure hashes.

Directory traversal vulnerability in Django 1.4.x before 1.4.7, 1.5.x before 1.5.3, and 1.6.x before 1.6 beta 3 allows remote attackers to read arbitrary files via a file path in the ALLOWEDINCLUDEROOTS setting followed by a .. (dot dot) in a ssi template tag.

It was reported that Django's built-in parsing of the Host header was incorrectly handling username/password information (in django.http.HttpRequest.gethost()). This could allow a remote attacker to cause parts of Django, in particular the password-reset mechanism, to generate and display arbitrary URLs to end-users.

Acknowledgements:

Red Hat would like to thank the upstream Django project for reporting this vulnerability.

The utils.http.issafeurl function in Django before 1.8.10 and 1.9.x before 1.9.3 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks or possibly conduct cross-site scripting (XSS) attacks via a URL containing basic authentication, as demonstrated by http://mysite.example.com\@attacker.com.

Django before 1.4.21, 1.5.x through 1.6.x, 1.7.x before 1.7.9, and 1.8.x before 1.8.3 uses an incorrect regular expression, which allows remote attackers to inject arbitrary headers and conduct HTTP response splitting attacks via a newline character in an (1) email message to the EmailValidator, a (2) URL to the URLValidator, or unspecified vectors to the (3) validateipv4address or (4) validateslug validator.

validators.URLValidator in Django 1.8.x before 1.8.3 allows remote attackers to cause a denial of service (CPU consumption) via unspecified vectors.

The cookie parsing code in Django before 1.8.15 and 1.9.x before 1.9.10, when used on a site with Google Analytics, allows remote attackers to bypass an intended CSRF protection mechanism by setting arbitrary cookies.

The issafeurl function in utils/http.py in Django 1.4.x before 1.4.6, 1.5.x before 1.5.2, and 1.6 before beta 2 treats a URL's scheme as safe even if it is not HTTP or HTTPS, which might introduce cross-site scripting (XSS) or other vulnerabilities into Django applications that use this function, as demonstrated by "the login view in django.contrib.auth.views" and the javascript: scheme.

The administrative interface (contrib.admin) in Django before 1.4.14, 1.5.x before 1.5.9, 1.6.x before 1.6.6, and 1.7 before release candidate 3 does not check if a field represents a relationship between models, which allows remote authenticated users to obtain sensitive information via a tofield parameter in a popup action to an admin change form page, as demonstrated by a /admin/auth/user/?pop=1&t=password URI.

The contrib.auth.middleware.RemoteUserMiddleware middleware in Django before 1.4.14, 1.5.x before 1.5.9, 1.6.x before 1.6.6, and 1.7 before release candidate 3, when using the contrib.auth.backends.RemoteUserBackend backend, allows remote authenticated users to hijack web sessions via vectors related to the REMOTEUSER header.

The utils.http.issafeurl function in Django before 1.4.20, 1.5.x, 1.6.x before 1.6.11, 1.7.x before 1.7.7, and 1.8.x before 1.8c1 does not properly validate URLs, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a control character in a URL, as demonstrated by a \x08javascript: URL.

The utils.html.striptags function in Django 1.6.x before 1.6.11, 1.7.x before 1.7.7, and 1.8.x before 1.8c1, when using certain versions of Python, allows remote attackers to cause a denial of service (infinite loop) by increasing the length of the input string.

The default configuration for the file upload handling system in Django before 1.4.14, 1.5.x before 1.5.9, 1.6.x before 1.6.6, and 1.7 before release candidate 3 uses a sequential file name generation process when a file with a conflicting name is uploaded, which allows remote attackers to cause a denial of service (CPU consumption) by unloading a multiple files with the same name.

The core.urlresolvers.reverse function in Django before 1.4.14, 1.5.x before 1.5.9, 1.6.x before 1.6.6, and 1.7 before release candidate 3 does not properly validate URLs, which allows remote attackers to conduct phishing attacks via a // (slash slash) in a URL, which triggers a scheme-relative URL to be generated.

The session backends in Django before 1.4.21, 1.5.x through 1.6.x, 1.7.x before 1.7.9, and 1.8.x before 1.8.3 allows remote attackers to cause a denial of service (session store consumption) via multiple requests with unique session keys.

Django 1.9.x before 1.9.2, when ModelAdmin.saveas is set to True, allows remote authenticated users to bypass intended access restrictions and create ModelAdmin objects via the "Save as New" option when editing objects and leveraging the "change" permission.

Cross-site scripting (XSS) vulnerability in the contents function in admin/helpers.py in Django before 1.7.6 and 1.8 before 1.8b2 allows remote attackers to inject arbitrary web script or HTML via a model attribute in ModelAdmin.readonlyfields, as demonstrated by an @property.