CVE-2026-100187 in AIL Framework
Summary
by MITRE • 09/25/2026
The Onion module in AIL Framework contained a performance shortcut in its URL extraction logic that accepted URLs as valid .onion targets based solely on a length check (exactly 69 characters) and a suffix check (ending in ".onion"), without performing proper hostname parsing or onion-domain validation. An unauthenticated attacker who could publish or control web content crawled by the framework could embed a crafted URL containing an IP address or non-onion hostname with a path ending in ".onion" that satisfied the length and suffix conditions. Such a URL would be extracted, its domain naively sliced from the string, and queued as a legitimate onion crawler task. This allowed unauthenticated content publishers to inject arbitrary non-onion targets into the crawler's task queue, influencing crawler behavior and potentially directing it toward unintended network resources. The vulnerability required no authentication, no user interaction, and only the ability to place crafted content in a location the framework would crawl. The security impact is a loss of integrity in the crawler's target selection: the framework processes and acts upon URLs that do not correspond to legitimate .onion services.
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Analysis
by VulDB Data Team • 09/25/2026
The AIL Framework serves as an advanced intelligence gathering tool designed for automated analysis, enrichment, and correlation of cyber threat data from various open-source feeds. Within this ecosystem, the Onion module plays a critical role in discovering and analyzing hidden service addresses on the Tor network. The security flaw identified within this module stems from a fundamental weakness in its URL extraction logic, specifically regarding how it validates and processes .onion domain names. Instead of implementing robust hostname parsing or utilizing established libraries for onion-domain validation, the framework relied on simplistic heuristic checks. These checks consisted solely of verifying that a candidate string was exactly sixty-nine characters long and ended with the suffix ".onion". This approach represents a classic case of insufficient input validation where structural assumptions are prioritized over semantic correctness, leading to a significant bypass of intended security controls.
The technical nature of this vulnerability allows an unauthenticated attacker who has the ability to publish or control web content that is crawled by the AIL Framework to inject malicious targets into the system's processing pipeline. By crafting a URL that contains an IP address or a standard non-onion hostname but appending a path segment ending in ".onion" such that the total length matches sixty-nine characters, an attacker can trick the extraction logic into treating it as a valid onion service. The framework naively slices this domain from the string and queues it for crawling without verifying whether the target actually resolves to a Tor hidden service or adheres to the specific cryptographic naming conventions required by the .onion namespace. This lack of deep inspection means that arbitrary network resources, including internal corporate infrastructure or external third-party services, can be targeted through this mechanism.
The operational impact of this vulnerability is primarily centered on the loss of integrity within the crawler's target selection process. Because the framework processes and acts upon URLs that do not correspond to legitimate .onion services, it may direct its scanning resources toward unintended network assets. This misdirection can lead to inaccurate intelligence outputs, as data collected from non-onion sources might be incorrectly attributed to Tor hidden services in subsequent analysis stages. Furthermore, if the crawler is configured with elevated privileges or access to sensitive internal networks, this flaw could potentially facilitate unauthorized reconnaissance of those environments. The attacker does not require authentication nor user interaction, relying instead on the passive act of placing crafted content in a location that falls within the framework's crawling scope, making exploitation straightforward and difficult to detect through traditional means.
From a classification perspective, this vulnerability aligns with CWE-20 Improper Input Validation, as the system fails to verify that inputs meet specified requirements before processing them. It also relates to CWE-749 Exposed Dangerous Method or API if the crawling functionality is considered an exposed interface susceptible to manipulation. In terms of adversary tactics, this behavior mirrors techniques found in the MITRE ATT&CK framework under T1583 Acquire Infrastructure, where attackers establish resources like domains or servers for use in subsequent attacks, and potentially T1046 Network Service Discovery if the crawler is used to map internal network services by accident. The vulnerability highlights the risks associated with trusting superficial string properties over rigorous protocol-level validation when handling external data sources.
To mitigate this risk, developers must replace the naive length and suffix checks with a robust hostname parsing mechanism that strictly validates .onion addresses against known Tor naming conventions. This includes verifying that the address consists of sixteen characters followed by ".onion" for version 2 onions or fifty-six characters followed by ".onion" for version 3 onions, ensuring no additional path components are misinterpreted as part of the domain name. Implementing a dedicated library for onion validation rather than custom regex logic will significantly reduce the attack surface. Additionally, introducing sandboxed execution environments for crawling tasks can limit the potential impact if an invalid target is processed. Regular security audits focusing on input sanitization and output encoding practices in automated intelligence gathering tools are essential to prevent similar integrity violations in future versions of the framework.