CVE-2012-5490: Cross-Site Scripting (XSS) Vulnerability in Plone
Summary
CVE-2012-5490: Cross-site scripting (XSS) vulnerability in kssdevel.py in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors. Affects plone across 2 version ranges.
< 4.2.3
>= 4.3a0, < 4.3b1
Fixed in 4.2.3 or 4.3b1, depending on the release line you run. How to fix ↓
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Background
Plone is an open-source content management system (CMS) written in Python and based on the Zope application server. It provides a user-friendly interface for managing websites, intranets, and collaborative workspaces. Plone is widely used for its robustness, extensibility, and security features. However, prior to version 4.2.3 and 4.3 beta 1, Plone was susceptible to a cross-site scripting (XSS) vulnerability in the 'kssdevel.py' module. This vulnerability allowed remote attackers to inject arbitrary web script or HTML into Plone websites.
Vulnerability Detail
The cross-site scripting (XSS) vulnerability in Plone stemmed from a lack of proper input sanitization in the 'kssdevel.py' module. Attackers could exploit this vulnerability by injecting malicious script or HTML code into Plone websites, which would then be executed in the context of unsuspecting users. This could lead to various security risks, including session hijacking, defacement of web pages, and theft of sensitive information. The exact vectors for exploitation were not specified in the vulnerability details.
How To Fix
Latest published version: 6.2.2 as of 23 Oct 2026
pip install --upgrade "plone==6.2.2"Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 4.2.34.2.3pip install --upgrade "plone==4.2.3" -
>= 4.3a0, < 4.3b14.3b1pip install --upgrade "plone==4.3b1"
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
No specific workaround was mentioned in the vulnerability details. However, as a general best practice, website administrators can implement input validation and output encoding to prevent XSS attacks. Additionally, using a web application firewall (WAF) can provide an additional layer of protection against such vulnerabilities.
Conclusion
The cross-site scripting (XSS) vulnerability in Plone prior to version 4.2.3 and 4.3 beta 1 posed a significant security risk to websites using the affected versions. Upgrading to the recommended versions or implementing input validation and output encoding can help mitigate this vulnerability. For further assistance and support in addressing this vulnerability, please contact DevNack.com.
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FAQ
Cross-site scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. This can lead to various attacks, such as session hijacking, defacement, and data theft.
You can use Vulert's vulnerability playground at Vulert Scanner to check if your Plone installation is affected by this specific vulnerability. Simply provide your Pipfile.lock, and Vulert will analyze it for any open-source vulnerabilities, including this XSS vulnerability.
The vulnerability details did not mention any specific known exploits. However, it is crucial to address this vulnerability promptly to prevent potential exploitation by attackers.
While upgrading to the latest Plone version is the recommended solution, you can also implement input validation and output encoding in your Plone website's code to mitigate the risk of XSS attacks. However, this approach may not provide the same level of security as the patched versions.
You can refer to the Plone security advisories and the Plone security mailing list for more information about security vulnerabilities in Plone. These resources provide timely updates, patches, and recommendations to ensure the security of your Plone installations.
References
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