When you visit a page where you need to login, Plone 2.5-5.1rc1 sends you to the login form with a 'came_from' parameter set to the previous url. After you login, you get redirected to the page you tried to view before. An attacker might try to abuse this by letting you click on a specially crafted link. You would login, and get redirected to the site of the attacker, letting you think that you are still on the original Plone site. Or some javascript of the attacker could be executed. Most of these types of attacks are already blocked by Plone, using the `isURLInPortal` check to make sure we only redirect to a page on the same Plone site. But a few more ways of tricking Plone into accepting a malicious link were discovered, and fixed with this hotfix.

Multiple cross-site request forgery (CSRF) vulnerabilities in Zope Management Interface 4.3.7 and earlier, and Plone before 5.x.

Cross-site scripting (XSS) vulnerability in Plone 3.3.0 through 3.3.6, 4.0.0 through 4.0.10, 4.1.0 through 4.1.6, 4.2.0 through 4.2.7, 4.3.x before 4.3.7, and 5.0rc1.

Plone 3.3.0 through 3.3.6, 4.0.0 through 4.0.10, 4.1.0 through 4.1.6, 4.2.0 through 4.2.7, 4.3.0 through 4.3.6, and 5.0rc1 allows remote attackers to add a new member to a Plone site with registration enabled, without acknowledgment of site administrator.

Plone 4.x through 4.3.11 and 5.x through 5.0.6 allow remote attackers to bypass a sandbox protection mechanism and obtain sensitive information by leveraging the Python string format method.

Multiple cross-site scripting (XSS) vulnerabilities in the ZMI page in Zope2 in Plone CMS 5.x through 5.0.6, 4.x through 4.3.11, and 3.3.x through 3.3.6 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Cross-site scripting (XSS) vulnerability in an unspecified page template in Plone CMS 5.x through 5.0.6, 4.x through 4.3.11, and 3.3.x through 3.3.6 allows remote attackers to inject arbitrary web script or HTML via unknown vectors.

Cross-site scripting (XSS) vulnerability in the URL checking infrastructure in Plone CMS 5.x through 5.0.6, 4.x through 4.3.11, and 3.3.x through 3.3.6 allows remote attackers to inject arbitrary web script or HTML via a crafted URL.

Multiple open redirect vulnerabilities in Plone CMS 5.x through 5.0.6, 4.x through 4.3.11, and 3.3.x through 3.3.6 allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in the referer parameter to (1) %2b%2bgroupdashboard%2b%2bplone.dashboard1%2bgroup/%2b/portlets.Actions or (2) folder/%2b%2bcontextportlets%2b%2bplone.footerportlets/%2b /portlets.Actions or the (3) came_from parameter to /login_form.

z3c.form in Plone CMS 5.x through 5.0.6 and 4.x through 4.3.11 allows remote attackers to conduct cross-site scripting (XSS) attacks via a crafted GET request.

Directory traversal vulnerability in Plone CMS 5.x through 5.0.6 and 4.2.x through 4.3.11 allows remote administrators to read arbitrary files via a .. (dot dot) in the path parameter in a getFile action to Plone/++theme++barceloneta/@@plone.resourceeditor.filemanager-actions.

Plone 3.3 through 5.1a1 allows remote attackers to obtain information about the ID of sensitive content via unspecified vectors.

Plone 4.0 through 5.1a1 does not have security declarations for Dexterity content-related WebDAV requests, which allows remote attackers to gain webdav access via unspecified vectors.

Cross-site scripting (XSS) vulnerability in the manage_findResult component in the search feature in Zope ZMI in Plone before 4.3.12 and 5.x before 5.0.7 allows remote attackers to inject arbitrary web script or HTML via vectors involving double quotes, as demonstrated by the obj_ids:tokens parameter. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-7140.

Zope before 2.13.19, as used in Plone before 4.2.3 and 4.3 before beta 1, does not reseed the pseudo-random number generator (PRNG), which makes it easier for remote attackers to guess the value via unspecified vectors. NOTE: this issue was SPLIT from CVE-2012-5508 due to different vulnerability types (ADT2).

The error pages in Plone before 4.2.3 and 4.3 before beta 1 allow remote attackers to obtain random numbers and derive the PRNG state for password resets via unspecified vectors. NOTE: this identifier was SPLIT per ADT2 due to different vulnerability types. CVE-2012-6661 was assigned for the PRNG reseeding issue in Zope.

The batch id change script (renameObjectsByPaths.py) in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to change the titles of content items by leveraging a valid CSRF token in a crafted request.

AccessControl/AuthEncoding.py in Zope before 2.13.19, as used in Plone before 4.2.3 and 4.3 before beta 1, allows remote attackers to obtain passwords via vectors involving timing discrepancies in password validation.

python_scripts.py in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to cause a denial of service (infinite loop) via an RSS feed request for a folder the user does not have permission to access.

atat.py in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to read private data structures via a request for a view without a name.