CVE-2021-29447 is a high-severity vulnerability affecting WordPress, specifically related to XML parsing issues in the Media Library. This vulnerability allows an authenticated user, such as an Author, to exploit the system if it is running PHP 8, potentially leading to XML External Entity (XXE) attacks. Successful exploitation may grant unauthorized access to internal files, which poses a significant risk to organizations using affected versions of WordPress.
The CVSS score for this vulnerability is 7.1, indicating a high severity level. This highlights the importance of addressing the issue promptly, particularly given the ease of exploitation due to low attack complexity and the requirement for low privileges. The vulnerability was disclosed on April 15, 2021, and has been patched in WordPress version 5.7.1, along with previous affected versions through a minor release.
Organizations using WordPress are strongly advised to ensure that auto-updates are enabled to protect against this and other vulnerabilities. The risk to organizations includes unauthorized access to sensitive internal files, which can lead to further compromise if exploited by malicious actors.
Given the potential for significant impact, organizations must prioritize patching immediately to mitigate risks associated with this vulnerability.
Vulnerability Details
This vulnerability allows an authenticated user to exploit an XML parsing issue in the Media Library of WordPress installations using PHP 8. The issue is categorized under CWE-611: Improper Restriction of XML External Entity Reference in DTDs. The CVSS v3.1 score from different sources varies slightly, with a primary score of 6.5 indicating medium severity from NVD, while the GitHub advisory scores it as high with a score of 7.1.
The vulnerability affects all versions of WordPress prior to 5.7.1. The publication date of the vulnerability was April 15, 2021, and it has since been modified to indicate the patches released.
Technical Analysis
The root cause of this vulnerability stems from an XML parsing issue that can be exploited via file uploads. The attack vector is network-based, allowing attackers to leverage this vulnerability remotely without requiring direct access to the system. The attack complexity is low, meaning that even users with minimal technical knowledge can potentially carry out the attack.
Privileges required for the attack are low, as authenticated users can initiate the exploitation. Notably, user interaction is not required to exploit this vulnerability. The impact on confidentiality is high, as attackers may gain access to sensitive internal files, while the integrity impact is low, and availability is unaffected.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2021-29447 is significant due to the potential for unauthorized access to sensitive internal files. Organizations must consider the blast radius potential, particularly in environments where WordPress is widely used or integrated with other systems. The urgency for addressing this vulnerability is high, given its exploitation status, which affects installations using PHP 8 and earlier versions of WordPress.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include all versions of WordPress prior to 5.7.1. Additionally, Debian Linux versions 9.0 and 10.0 are also vulnerable. Organizations should ensure they update to the latest version to mitigate this risk.
Mitigation & Remediation
Organizations should prioritize updating WordPress to version 5.7.1 or later to address this vulnerability. Keeping auto-updates enabled is highly recommended to ensure that any future vulnerabilities are promptly patched. In cases where immediate patching is not feasible, consider implementing network controls to limit access to the WordPress installation, as well as conducting configuration hardening to minimize the attack surface.
For further guidance on maintaining security, organizations may refer to resources such as the continuous penetration testing services to identify and remediate vulnerabilities proactively.
Detection Guidance
To detect potential exploitation attempts related to this vulnerability, organizations should monitor logs for unusual file upload activities, particularly those involving XML files. Additionally, look for behavioral anomalies that may indicate unauthorized access attempts, such as unexpected file reads or access to sensitive directories.
AppSecure Threat Intelligence Insight
CVE-2021-29447 represents a notable security risk within the WordPress ecosystem, particularly as it is related to XML parsing vulnerabilities that have been historically exploited. Security teams should analyze this vulnerability for patterns that could indicate similar weaknesses in other systems, emphasizing the importance of regular security assessments.
As part of a proactive security posture, organizations should engage in practices that include vulnerability management and regular assessments to stay ahead of potential threats.
Additionally, organizations should consider implementing penetration testing methodologies that focus on identifying and mitigating XML-related vulnerabilities.
Overall, CVE-2021-29447 serves as a reminder of the necessity for continuous vigilance and adaptation in security practices.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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