CVE-2026-95653 in Community Store
Summary
by MITRE • 09/22/2026
Concrete CMS Community Store before 2.7.8 derives digital product download tokens from order creation timestamps instead of random values, making tokens predictable. Unauthenticated attackers can enumerate sequential order and file identifiers to calculate valid download tokens and retrieve digital goods purchased by other customers.
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Analysis
by VulDB Data Team • 09/22/2026
The vulnerability in Concrete CMS Community Store prior to version 2.7.8 represents a critical failure in the implementation of access control mechanisms for digital product downloads, specifically classified under CWE-345: Insufficient Verification of Data Authenticity and CWE-613: Insufficient Session Expiration or Termination when considering the predictability aspect as a form of session identifier weakness. The core technical flaw lies in the algorithmic generation of download tokens used to authorize access to purchased digital files. Instead of employing cryptographically secure random number generators to create unique, unpredictable identifiers for each transaction, the system derives these tokens directly from the timestamp of order creation. This design choice introduces a deterministic relationship between the time an order was placed and the resulting authorization token, effectively reducing the entropy space available to attackers and allowing them to reverse-engineer valid credentials based on temporal data.
From an operational perspective, this flaw enables unauthenticated adversaries to perform sequential enumeration attacks against both order identifiers and file identifiers within the system. By understanding that download tokens are time-based derivations, an attacker can calculate a window of probable timestamps associated with recent transactions. Coupled with the ability to enumerate sequential database IDs for orders and files, which is often possible due to predictable ID increments in many web applications, the attacker can generate a high volume of potential valid download links. This allows them to bypass authentication checks entirely, accessing digital goods that were purchased by other customers without any form of legitimate authorization or payment verification. The attack does not require prior access credentials, making it particularly dangerous as it can be executed remotely over standard network protocols with minimal effort and tooling.
The impact of this vulnerability extends beyond simple unauthorized access to intellectual property. It constitutes a significant breach of confidentiality for customer data and commercial assets, potentially violating privacy regulations such as GDPR or CCPA if personal information is exposed alongside the digital goods. Furthermore, it undermines the integrity of the e-commerce platform by allowing theft of services that are intended to be restricted to paying customers only. This can lead to direct financial losses for merchants who rely on these sales and erodes trust among legitimate users whose purchases may be compromised. The ability to retrieve files purchased by others also opens avenues for further exploitation, such as analyzing proprietary code or media content for additional vulnerabilities or competitive intelligence gathering.
Mitigation strategies must focus on replacing the deterministic token generation logic with a robust cryptographic approach immediately upon upgrading to version 2.7.8 or later, where this issue has been addressed. For systems that cannot be upgraded instantly, administrators should implement compensating controls such as enforcing strict rate limiting on download endpoints to mitigate enumeration attempts and ensuring that order IDs are not sequential or easily guessable by randomizing database ID generation if possible. Additionally, implementing short-lived session tokens with absolute expiration times rather than relying solely on static identifiers can reduce the window of opportunity for attackers. Regular security audits focusing on access control logic and input validation patterns are essential to prevent similar issues in custom modules or future updates within the Concrete CMS ecosystem.