A significant security vulnerability, titled CVE-2023-47260, has been discovered in the popular project management software, Redmine. This vulnerability allows an attacker to carry out a cross-site scripting (XSS) attack on systems running Redmine prior to versions 4.2.11 and 5..6 via the use of maliciously crafted thumbnails. In this post, we will take a deep dive into the exploit details, discuss the affected Redmine versions, examine the proof-of-concept code, and provide references to the original sources.

Exploit Details

An attacker can exploit the CVE-2023-47260 vulnerability in Redmine by crafting a malicious thumbnail, which when viewed by a victim, would execute arbitrary JavaScript code in the context of the victim's browser. This can lead to a potential leak in sensitive information or allow the attacker to carry out further attacks on the affected Redmine instance.

Affected Redmine Versions

The vulnerability affects Redmine installations that are running on versions before 4.2.11 and 5..x before 5..6. Users of these versions are strongly encouraged to upgrade to the latest version to address this security flaw.

Proof-of-Concept

To demonstrate the vulnerability, an attacker can craft the following payload to create a malicious thumbnail:

<img src=x onerror=alert(1)>

This HTML code snippet contains an image source ("src") that is invalid, which will trigger the "onerror" event. The "onerror" event is set to execute the JavaScript "alert()" function, visibly alerting the user with a pop-up message. In a real-world scenario, this could be replaced with more dangerous JavaScript intended to steal sensitive data or compromise the security of users or the Redmine instance.

Once the attacker uploads this payload as a thumbnail in a vulnerable Redmine version, any user viewing that thumbnail will trigger the execution of the JavaScript code "alert(1)" in the context of their browser.

Resolution & Mitigation

To resolve this vulnerability, users of affected Redmine versions should upgrade to either version 4.2.11 or version 5..6, which contain the necessary patches to protect against this XSS vulnerability. Users can download the updated versions from the official Redmine website at the following links:

- Redmine 4.2.11: https://www.redmine.org/releases/redmine-4.2.11.tar.gz
- Redmine 5..6: https://www.redmine.org/releases/redmine-5..6.tar.gz

Administrators should also be aware of and teach users about the risks posed by XSS attacks in general. Educated users are less likely to fall victim to such attacks and can assist in identifying potential vulnerabilities in software systems.

Original Sources & References

For further information regarding this vulnerability and its details, the following resources can be helpful:

- The CVE entry for this vulnerability (CVE-2023-47260): https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-47260
- The official Redmine security advisory detailing the issue and the affected versions: https://www.redmine.org/news/143

In conclusion, XSS vulnerabilities like CVE-2023-47260 in Redmine can be detrimental to user security and the overall trustworthiness of a software application. It is crucial to keep software systems up-to-date with the latest patches to prevent security breaches and ensure the integrity of data and user accounts.

Timeline

Published on: 11/05/2023 04:15:10 UTC
Last modified on: 11/14/2023 18:30:09 UTC