CVE-2023-27592 : Vulnerability Insights and Analysis

This CVE involves a Stored XSS vulnerability in Miniflux when opening a broken image due to an unescaped ServerError in the proxy handler. The vulnerability has been assigned a CVSS base score of 4.8, indicating a medium severity issue.

Understanding CVE-2023-27592

Miniflux, a feed reader application, is affected by this vulnerability. The issue arises from the handling of outbound requests made by the Go HTTP client, leading to the injection of malicious JavaScript code through a crafted RSS feed.

What is CVE-2023-27592?

The vulnerability allows an attacker to execute arbitrary JavaScript on a victim's Miniflux instance by luring them to open a broken image within a specially-crafted RSS feed. This could potentially lead to sensitive actions being performed on the Miniflux instance and even grant administrative access to the attacker.

The Impact of CVE-2023-27592

Exploitation of this vulnerability could result in unauthorized execution of JavaScript within the Miniflux application, posing a risk of data compromise and unauthorized access to the system. Administrators and users of affected Miniflux versions are particularly at risk.

Technical Details of CVE-2023-27592

The vulnerability arises from the unescaped ServerError in the proxy handler when handling failed outbound requests. The affected version range of Miniflux is from 2.0.25 to less than 2.0.43.

Vulnerability Description

When an invalid URL is specified in the

srcset

attribute of an

<img>

tag within the RSS feed, the proxy handler can be tricked into returning the invalid URL unescaped, leading to the execution of arbitrary JavaScript code.

Affected Systems and Versions

Miniflux version 2.0.25 to less than 2.0.43 is confirmed to be impacted by this vulnerability. Users of these versions are advised to take immediate action to mitigate the risk.

Exploitation Mechanism

By enticing a user to open a broken image within a specially-crafted RSS feed, an attacker can trigger the execution of malicious JavaScript within the Miniflux application.

Mitigation and Prevention

To address CVE-2023-27592 and protect Miniflux instances from potential exploitation, users are recommended to implement the following measures:

Immediate Steps to Take

Update to the patched version, 2.0.43, to address the vulnerability.
Disable the image proxy feature as a temporary workaround to mitigate the risk of executing malicious JavaScript.

Long-Term Security Practices

Regularly apply software patches and updates to ensure the security of the application.
Educate users on safe browsing practices to reduce the likelihood of falling victim to social engineering attacks.

Patching and Updates

Miniflux has released version 2.0.43, which contains the necessary patches to mitigate the Stored XSS vulnerability. Users are strongly encouraged to upgrade to this version or newer to protect their systems from potential exploitation.