NewsPublished 25 Sep 2025

Yet Another Random Story. VBScript's Randomize Internals.

Source Reddit NetSec

Description

Yet Another Random Story. VBScript's Randomize Internals. Source: https://blog.doyensec.com/2025/09/25/yet-another-random-story.html

Impact

For European organizations, the impact of this issue is primarily relevant to those still using legacy systems or applications that rely on VBScript, particularly in environments where VBScript is used for automation, legacy web applications, or internal tools. Predictable random number generation can lead to compromised confidentiality and integrity if attackers can guess tokens, session IDs, or cryptographic keys derived from VBScript's Randomize function. This could facilitate unauthorized access, session hijacking, or data manipulation. However, given the declining use of VBScript in modern environments and the lack of known exploits, the immediate risk is limited. Organizations with legacy Windows infrastructure, especially those running older versions of Internet Explorer or legacy automation scripts, may be more vulnerable. The threat is less likely to affect cloud-native or modern application stacks prevalent in Europe. Nonetheless, sectors with critical legacy systems, such as manufacturing, utilities, or government agencies, should be aware of this potential weakness as part of their broader risk assessments.

Defensive guidance

European organizations should conduct an inventory of systems and applications that utilize VBScript, particularly those employing the Randomize function for security-related randomness. Where possible, migrate away from VBScript to modern scripting languages or frameworks with robust, cryptographically secure random number generators. For legacy systems that cannot be replaced immediately, implement compensating controls such as additional entropy sources, external cryptographic libraries, or application-layer randomness enhancements. Regularly review and update legacy scripts to minimize reliance on predictable randomness. Additionally, monitor for unusual authentication or session activity that could indicate exploitation attempts. Educate developers and system administrators about the limitations of VBScript's Randomize function and encourage secure coding practices. Finally, maintain up-to-date endpoint protection and network monitoring to detect potential exploitation attempts targeting legacy scripting environments.

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Description

AI analysisMachine-generated, updated 25 Sep 2025, 10:52 UTC

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