CVE-2026-27490 in iTop
Summary
by MITRE • 08/21/2026
Combodo iTop is a web based IT service management tool. Prior to 3.2.3, inline images that are accessible without being authenticated are protected by a weak 24-bit pseudo-random secret. This issue has been fixed in version 3.2.3.
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Analysis
by VulDB Data Team • 08/21/2026
The vulnerability identified within Combodo iTop prior to version 3.2.3 represents a significant flaw in the implementation of access controls for inline images, specifically stemming from an inadequate reliance on security through obscurity rather than robust authentication mechanisms. In many web-based applications, particularly those dealing with IT service management and potentially sensitive operational data, it is common practice to protect certain dynamic resources using unique identifiers or tokens appended to URLs. The developers of iTop attempted to secure these inline images by employing a pseudo-random secret string intended to prevent unauthorized users from guessing the URL structure and accessing protected content without proper credentials. However, the entropy of this protective mechanism was critically insufficient, relying on a 24-bit random value which provides only approximately sixteen million possible combinations. This level of randomness is trivially susceptible to brute-force attacks in modern computing environments where high-speed network connections and parallel processing capabilities allow an attacker to iterate through millions of potential secret values per second.
From a technical perspective, this flaw constitutes a classic example of insufficient entropy in security tokens, which aligns with CWE-330: Use of Insufficiently Random Values. The core issue lies not necessarily in the logic of using a token for access control but in the mathematical weakness of that token itself. A 24-bit random number is far below the industry standard minimum recommendation of 128 bits, which is widely accepted as necessary to resist brute-force enumeration attacks over reasonable timeframes. By exposing these inline images via URLs containing this weak secret, the application inadvertently created a predictable attack surface. An attacker does not need valid user credentials or session cookies to access these resources; they only need to systematically guess the correct combination of parameters that constitute the protected URL path. This bypasses the intended authentication layer entirely, allowing unauthenticated actors to retrieve data that was meant to be restricted to authorized personnel.
The operational impact of this vulnerability is substantial for organizations utilizing Combodo iTop as their primary IT service management platform. Inline images often contain visual representations of tickets, status indicators, or even embedded metadata related to specific incidents and change requests. If an attacker successfully enumerates these secrets, they can gain unauthorized access to a wide array of information that may include sensitive business logic, internal process statuses, employee names associated with ticket assignments, or other contextual data visible within the image content itself. This constitutes a direct violation of confidentiality principles and could facilitate further reconnaissance activities against the organization's IT infrastructure. The ability to scrape this visual data without authentication lowers the barrier for entry significantly, potentially serving as an initial foothold for more sophisticated attacks such as social engineering campaigns based on gathered intelligence or deeper network mapping exercises that rely on understanding internal workflows and structures depicted in these images.
To mitigate this vulnerability effectively, organizations must ensure they are running Combodo iTop version 3.2.3 or later, where the underlying implementation has been corrected to utilize stronger cryptographic random number generation for access tokens. For environments where immediate patching is not feasible due to operational constraints, temporary mitigations should focus on restricting direct web server access to these specific image directories if possible, although this may impact legitimate functionality depending on how the application renders content. Additionally, implementing strict rate limiting and IP-based throttling at the reverse proxy or firewall level can help detect and block rapid enumeration attempts characteristic of brute-force attacks against weak token spaces. It is also advisable to review other areas of the application for similar patterns where security relies on obscure URLs rather than explicit authentication checks, ensuring alignment with broader industry standards such as OWASP guidelines which emphasize that access control decisions must never be based solely on URL structure or hidden fields. Long-term resilience requires adopting a defense-in-depth strategy where even if one layer fails due to weak randomness, other controls like session management and role-based access restrictions remain intact to protect sensitive assets from unauthorized disclosure.