CVE-2026-84483

Received Received - Intake

Authentication Bypass in AVideo via HMAC Token Forgery

Publication date: 2026-09-01

Last updated on: 2026-09-01

Assigner: VulnCheck

Description

WWBN AVideo through commit 9c39d8c8 contains an incomplete authentication bypass in encryptPass.json.php that allows unauthenticated attackers to compute valid HMAC tokens using the public site URL and current time. Attackers can forge authentication tokens by computing hash_hmac with the site's base URL as the key and submit arbitrary passwords to receive encrypted hashes, enabling offline precomputation attacks against stolen password databases.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-01

Last Modified

2026-09-01

Generated

2026-09-02

AI Q&A

2026-09-02

EPSS Evaluated

N/A

NVD

CVE-2026-84483

EUVD

EUVD-2026-69725

Affected Vendors & Products

Vendor	Product	Version / Range
wwbn	avideo	to 9c39d8c8 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-321	The product uses a hard-coded, unchangeable cryptographic key.

Attack-Flow Graph

Executive Summary

This vulnerability in WWBN AVideo allows unauthenticated attackers to bypass authentication by forging HMAC tokens. Attackers can compute valid tokens using the site's public URL and current time, then submit arbitrary passwords to receive encrypted hashes. This enables offline attacks on stolen password databases.

Detection Guidance

Check for unauthorized access attempts to encryptPass.json.php or unusual HMAC token generation requests. Monitor logs for repeated password submission attempts or tokens generated without valid sessions.

Impact Analysis

An attacker could gain unauthorized access to user accounts without valid credentials. They might steal sensitive data, manipulate content, or perform actions on behalf of other users. The vulnerability also allows precomputation attacks on password databases.

Compliance Impact

This vulnerability could lead to unauthorized access to personal data, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Organizations may face legal penalties, reputational damage, and loss of compliance certifications.

Mitigation Strategies

Update AVideo to the latest commit or patch addressing this issue. Restrict access to encryptPass.json.php via server rules. Rotate all HMAC keys and invalidate any precomputed tokens.

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