CVE-2021-31747 in Pluck
Summary
by MITRE • 12/10/2021
Missing SSL Certificate Validation issue exists in Pluck 4.7.15 in update_applet.php, which could lead to man-in-the-middle attacks.
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Analysis
by VulDB Data Team • 12/15/2021
The CVE-2021-31747 vulnerability represents a critical security flaw in the Pluck content management system version 4.7.15, specifically within the update_applet.php component. This issue stems from insufficient SSL certificate validation mechanisms that leave the application susceptible to man-in-the-middle attacks. The vulnerability occurs when the system fails to properly verify SSL certificates during secure communications, creating an opportunity for attackers to intercept and potentially manipulate data transmitted between clients and servers. The flaw is particularly concerning as it directly impacts the integrity and confidentiality of communications within the application's update mechanisms, where sensitive operations and data exchanges take place.
The technical implementation of this vulnerability lies in the update_applet.php script which handles application updates and component installations. When the system attempts to establish secure connections for downloading updates or communicating with remote servers, it does not perform adequate certificate validation checks. This missing validation allows attackers to present fraudulent SSL certificates that would be accepted by the vulnerable system, effectively bypassing the security protections that SSL/TLS protocols are designed to provide. The vulnerability essentially removes the cryptographic assurance that data exchanged with remote servers remains authentic and unmodified, creating a pathway for attackers to inject malicious content or intercept sensitive information.
From an operational perspective, this vulnerability exposes Pluck 4.7.15 installations to significant risk during update processes and any communication requiring secure connections. Attackers could exploit this weakness to perform session hijacking, inject malicious code into update packages, or capture sensitive credentials and data transmitted during the update process. The impact extends beyond simple data interception as the vulnerability could enable complete compromise of the affected system through the installation of malicious updates. According to the CWE database, this issue maps to CWE-295 which specifically addresses improper certificate validation, while from an ATT&CK framework perspective it relates to T1041 for Exfiltration Over C2 Channel and T1566 for Phishing with Malicious Attachments, as attackers could leverage the vulnerability to deliver malicious payloads through compromised update mechanisms.
Organizations using Pluck 4.7.15 should immediately implement mitigations including updating to a patched version of the application, implementing additional network-level security controls such as certificate pinning, and monitoring for suspicious update activities. The recommended approach involves verifying that all SSL certificate validation is properly enforced during all secure communications, implementing strict certificate chain validation, and ensuring that the application enforces proper hostname verification. Security teams should also consider implementing network segmentation and intrusion detection systems to monitor for potential exploitation attempts. Additionally, administrators should review and validate all update sources to ensure they are legitimate and properly authenticated before any update installation occurs, as this vulnerability essentially undermines the trust model that secure update mechanisms rely upon.