CVE-2021-41258
7.3 · HIGHOverview
CVE-2021-41258 is a high-severity vulnerability affecting getkirby kirby. It was published on November 16, 2021 and has a CVSS 3.1 base score of 7.3 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.3, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Kirby is an open source file structured CMS. In affected versions Kirby's blocks field stores structured data for each block. This data is then used in block snippets to convert the blocks to HTML for use in your templates. We recommend to escape HTML special characters to protect against cross-site scripting (XSS) attacks. The default snippet for the image block unfortunately did not use our escaping helper. This made it possible to include malicious HTML code in the source, alt and link fields of the image block, which would then be displayed on the site frontend and executed in the browsers of site visitors and logged in users who are browsing the site. Attackers must be in your group of authenticated Panel users in order to exploit this weakness. Users who do not make use of the blocks field are not affected. This issue has been patched in Kirby version 3.5.8 by escaping special HTML characters in the output from the default image block snippet. Please update to this or a later ver
Remediation
Check the references section for vendor advisories and patches from getkirby. Update kirby to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| getkirby | kirby | 3.5.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-41258?
CVE-2021-41258 is a high-severity vulnerability affecting getkirby kirby. It was published on November 16, 2021 and has a CVSS 3.1 base score of 7.3 (HIGH).
How severe is CVE-2021-41258?
This vulnerability has a CVSS 3.1 base score of 7.3, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-41258?
Check the references section for vendor advisories and patches from getkirby. Update kirby to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-41258?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-41258 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related HIGH CVEs from 2021
View all →systeminformation is an open source system and OS information library for node.js. A command injecti
An Improper Access Control Privilege Escalation Vulnerability was discovered in the User Setting of
An SQL injection Privilege Escalation Vulnerability was discovered in the Orion Platform reported by
Insecure deserialization leading to Remote Code Execution was detected in the Orion Platform version
Insecure Deserialization of untrusted data remote code execution vulnerability was discovered in Pat
Deserialization of Untrusted Data in the Web Console Chart Endpoint can lead to remote code executio
Insecure Deseralization of untrusted data remote code execution vulnerability was discovered in Patc
SAP Web Dispatcher versions - 7.49, 7.53, 7.77, 7.81, KRNL64NUC - 7.22, 7.22EXT, 7.49, KRNL64UC -7.2
uploader.php in the KCFinder integration project through 2018-06-01 for Drupal mishandles validation
An issue was discovered in the PageLayer plugin before 1.1.2 for WordPress. The pagelayer_settings_p
MK-AUTH through 19.01 K4.9 allows CSRF for password changes via the central/executar_central.php?aca
IBM Cloud Pak System 2.3 is vulnerable to cross-site request forgery which could allow an attacker t