CVE-2015-3373 in Amazon AWS Module
Summary
by MITRE
The Amazon AWS module before 7.x-1.3 for Drupal uses the base URL and AWS access key to generate the access token, which makes it easier for remote attackers to guess the token value and create backups via a crafted URL.
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Analysis
by VulDB Data Team • 05/09/2022
The vulnerability identified as CVE-2015-3373 affects the Amazon AWS module for Drupal versions prior to 7.x-1.3, representing a critical security flaw in cloud service integration. This issue stems from the module's improper implementation of access token generation mechanisms, creating predictable cryptographic values that significantly weaken the security posture of Drupal installations relying on AWS services. The flaw specifically manifests in how the module constructs access tokens using only the base URL and AWS access key as input parameters, without incorporating sufficient entropy or randomization elements that would normally be expected in secure cryptographic operations.
The technical implementation of this vulnerability exposes a fundamental weakness in the module's token generation algorithm, where the predictable nature of the access token creation process allows malicious actors to perform brute force attacks or pattern analysis to deduce valid token values. This vulnerability falls under the category of weak cryptographic implementation as defined by CWE-327, specifically addressing the use of insufficient entropy in cryptographic operations. The attack vector is particularly dangerous because it enables remote exploitation through crafted URL parameters, allowing unauthorized users to potentially create unauthorized backups or access AWS resources without proper authentication.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally compromises the integrity of the cloud backup and storage mechanisms that Drupal administrators rely upon. Attackers can exploit this weakness to create unauthorized backups, potentially gaining access to sensitive data stored in AWS environments, or to perform unauthorized operations against the configured AWS resources. This vulnerability directly relates to ATT&CK technique T1078.004, which covers legitimate credentials in cloud environments, as the predictable token generation essentially provides attackers with a means to obtain valid credentials for AWS services. The implications are severe for organizations using Drupal for content management, particularly those with sensitive data stored in AWS infrastructure, as the vulnerability could lead to data breaches, unauthorized resource consumption, or complete compromise of cloud-based applications.
The security implications of CVE-2015-3373 demonstrate a classic example of how insecure randomization and predictable cryptographic operations can undermine even well-established security frameworks. Organizations using the affected Drupal module should immediately upgrade to version 7.x-1.3 or later, which implements proper token generation mechanisms incorporating sufficient entropy and randomization. Additional mitigations include implementing network-level restrictions to limit access to AWS endpoints, monitoring for unusual backup activities, and ensuring that AWS access keys are properly rotated. The vulnerability highlights the critical importance of proper cryptographic implementation in web applications and serves as a reminder that even seemingly simple security mechanisms like token generation require robust entropy sources and careful consideration of attack surfaces. This flaw also underscores the necessity of regular security audits and updates for third-party modules, as the vulnerability existed for an extended period before being properly addressed in the module's release cycle.