CVE-2021-21425 is a critical vulnerability affecting the getgrav grav-plugin-admin, with a CVSS score of 9.3. This vulnerability allows an unauthenticated user to execute certain methods of the administrator controller without requiring any credentials. Specifically, the vulnerability is present in versions 1.10.7 and earlier, and it can lead to arbitrary YAML file creation or modifications of existing YAML files on the system. The implications of this vulnerability are severe, as it can allow attackers to change site configurations, hijack administrator accounts, or execute operating system commands under the context of the web server user. Organizations must prioritize patching to version 1.10.8, where this vulnerability has been addressed.
In practical terms, the exploitation of this vulnerability exposes organizations to various risks, including unauthorized changes to website content, which can harm the organization’s reputation and lead to further attacks. The ease of exploitation, combined with the lack of authentication requirements, makes this vulnerability particularly dangerous. Organizations should implement immediate measures to block access to the /admin path from untrusted sources until a patch can be applied.
The urgency for defenders cannot be overstated. Organizations should implement the patch as soon as possible to avoid potential exploitation. The risk to organizations includes significant impacts on confidentiality, integrity, and availability due to the possibility of unauthorized command execution and configuration changes.
Given the high exploitability and critical nature of this vulnerability, it is essential for organizations utilizing the grav-plugin-admin to take proactive measures in their security posture.
Vulnerability Details
The official description of CVE-2021-21425 states that the Grav Admin Plugin provides an HTML user interface for configuring Grav and managing pages. The vulnerability allows unauthenticated users to execute methods of the administrator controller without credentials in versions 1.10.7 and earlier. Successful exploitation can lead to arbitrary YAML file creation or modification of existing YAML files, resulting in various configuration changes. This vulnerability is classified under CWE-284, indicating improper access control.
The vulnerability was published on April 7, 2021, and it has since been modified. The CVSS score is 9.3, indicating a critical severity level. The attack vector is classified as network-based, with low complexity and no privileges required for exploitation. The impacts on confidentiality are low, but the integrity impact is high, which emphasizes the seriousness of this vulnerability.
Technical Analysis
The root cause of CVE-2021-21425 is a lack of proper access control within the Grav Admin Plugin. Attackers may leverage this vulnerability to perform actions typically restricted to authenticated administrators. The attack vector is network-based, allowing remote exploitation by any unauthenticated user. The attack complexity is low, as no additional privileges or user interaction is needed for exploitation.
The vulnerability results in low confidentiality impact due to the limited data exposure, but the integrity impact is high as it allows modification of important configuration files. The availability impact is none, as the vulnerability does not disrupt service availability but can lead to significant changes in site behavior.
Risk & Impact Analysis
The real-world deployment risk of CVE-2021-21425 is substantial. Organizations using the affected Grav Admin Plugin may face unauthorized access to sensitive configurations, resulting in potential data breaches or account hijacking. Attackers can exploit this vulnerability to change web page content or execute commands in the context of the web server, which could lead to further exploitation of the underlying server.
The blast radius of this vulnerability extends to any organization utilizing the Grav content management system, particularly those without proper access controls in place. The urgency for remediation is critical, as the potential for exploitation is high given the ease of access. Organizations should address this vulnerability immediately to prevent unauthorized access and potential damage.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable versions of the grav-plugin-admin are all versions prior to 1.10.8. Organizations should ensure that they upgrade to this version or later to mitigate the risk associated with CVE-2021-21425.
Mitigation & Remediation
Organizations should prioritize patching to version 1.10.8 of the grav-plugin-admin. If immediate patching is not possible, a workaround is to block access to the /admin path from untrusted sources. Additionally, implementing robust security measures such as web application firewalls and regular security assessments can help mitigate potential risks.
For more comprehensive security practices, organizations can refer to our application security assessment services.
Detection Guidance
To detect potential exploitation of CVE-2021-21425, organizations should monitor logs for unusual access patterns to the /admin path, particularly from unauthenticated users. Behavioral anomalies and any unauthorized changes to YAML files should also be flagged for review.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-21425 lies in its demonstration of the risks associated with inadequate access control in web applications. This vulnerability highlights a common trend where misconfigurations can lead to severe security incidents.
Regular security assessments and adopting a proactive security posture can help organizations identify such vulnerabilities before they can be exploited. For further insights, organizations can explore our resources on vulnerability management programs, penetration testing methodology, and vulnerability assessment processes to enhance their defenses against such vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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