CVE-2026-28133 presents a high-severity vulnerability affecting the WP Chill Filr filr-protection plugin. This vulnerability allows for unrestricted uploads of files with dangerous types, which could potentially enable an attacker to upload a web shell to a web server. The affected versions include those up to 1.2.14, making it crucial for organizations using this plugin to take immediate action to mitigate the risk.
With a CVSS score of 8.5, this security flaw poses a significant risk to organizations, particularly due to its potential impact on confidentiality, integrity, and availability. The attack vector is categorized as network-based, and it is characterized by high attack complexity and low privileges required for exploitation. Given these factors, organizations should prioritize addressing this vulnerability in their patch management cycles.
Currently, there are no known exploits or public proof of concepts available, but the high severity of this vulnerability necessitates vigilance. Organizations should remain aware of any updates or patches from the vendor to ensure their systems are secured against potential threats.
Given the potential for severe consequences, organizations must treat this vulnerability with urgency and prioritize patching immediately. Delays in remediation could lead to unauthorized access and significant damage to systems.
Vulnerability Details
The vulnerability is characterized as an unrestricted upload of file with a dangerous type in the WP Chill Filr filr-protection plugin, allowing attackers to upload a web shell to a web server.
Officially classified under CWE-434, this vulnerability has a CVSS score of 8.5, indicating a high severity level. The affected product version range includes all versions up to and including 1.2.14, with the vulnerability first published on March 5, 2026.
Technical Analysis
The root cause of this vulnerability lies in the inadequate validation of file uploads by the WP Chill Filr plugin. Attackers can exploit this weakness to upload malicious files, specifically web shells, which can then be executed on the server.
The attack vector is network-based, requiring no user interaction, and it has a high attack complexity due to the need for specific file types to bypass validation mechanisms. Once a web shell is uploaded, attackers gain elevated privileges, which can lead to further exploitation of the server.
The impacts of this vulnerability are severe, with high confidentiality, integrity, and availability impacts. Organizations should be aware of the potential for data breaches and system compromises stemming from this exploit.
Risk & Impact Analysis
Organizations utilizing the WP Chill Filr plugin face substantial risks associated with CVE-2026-28133. The unrestricted file upload capability allows attackers to introduce malicious payloads into the server environment, which can lead to data breaches, unauthorized access, and service disruptions.
The blast radius for this vulnerability could encompass any system or network component relying on the affected plugin, potentially leading to widespread operational impacts. Given the high CVSS score and the nature of the vulnerability, organizations should prioritize remediation efforts in their patch management processes.
With an EPSS score indicating a potential probability of exploitation, the urgency to address this vulnerability is further emphasized. Organizations should schedule remediation into their priority patch cycles to mitigate the risk before any potential exploitation occurs.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects all versions of the WP Chill Filr plugin up to and including 1.2.14. Organizations should ensure that they update to the latest patched version to prevent exploitation.
Mitigation & Remediation
To mitigate this vulnerability, organizations should immediately update the WP Chill Filr plugin to the latest version. If a patch is unavailable, consider implementing workarounds such as restricting file upload types to only those that are necessary. Additionally, organizations should engage in continuous security practices, such as continuous penetration testing to identify and remediate similar vulnerabilities.
Detection Guidance
Organizations should monitor logs for indicators of unauthorized file uploads and unusual file types being executed on the server. Behavioral anomalies that suggest exploitation should be promptly investigated. Network signatures indicative of web shell activity should also be established.
AppSecure Threat Intelligence Insight
CVE-2026-28133 highlights the ongoing challenges posed by file upload vulnerabilities. Security teams should reflect on the patterns and trends represented by this vulnerability, particularly in the context of web application security. The risk associated with unrestricted file uploads remains a significant concern, underscoring the need for robust validation processes.
Lessons learned from such vulnerabilities should inform security strategies, and organizations should prioritize the implementation of secure coding practices to prevent similar issues. For insights on secure coding practices, organizations can refer to the secure coding practices guide provided by AppSecure.
Organizations should also consider conducting security assessments regularly to stay ahead of threats and vulnerabilities. For further guidance on conducting effective assessments, AppSecure offers a comprehensive application security assessment to help organizations identify vulnerabilities and improve their security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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