CVE-2025-8616: OpenText Advanced Authentication Bypass

CVE-2025-8616 Overview

CVE-2025-8616 is an authentication bypass vulnerability in OpenText Advanced Authentication. A malicious browser plugin can record the user authentication process and later replay it to bypass authentication controls. The flaw is classified under [CWE-294] (Authentication Bypass by Capture-replay).

The issue affects Advanced Authentication versions on or before 6.5.0. Exploitation requires user interaction and elevated attack complexity, but a successful replay can compromise account access without valid credentials at the time of the attack.

Critical Impact
A malicious browser extension can capture authentication artifacts and replay them to impersonate legitimate users, undermining the assurance provided by the multi-factor authentication platform.

Affected Products

OpenText Advanced Authentication 6.5.0
OpenText Advanced Authentication versions prior to 6.5.0
Browser-based authentication clients interacting with the affected server

Discovery Timeline

2025-08-06 - CVE-2025-8616 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-8616

Vulnerability Analysis

OpenText Advanced Authentication is a multi-factor authentication (MFA) platform that brokers various authenticators through a browser-facing workflow. The vulnerability allows a malicious browser plugin present in the user's browser to observe the authentication exchange as it occurs.

Because the authentication protocol does not sufficiently bind messages to a fresh session context, the recorded exchange can be replayed against the server. The server accepts the replayed messages as valid, granting the attacker access without needing to present live credentials or a fresh second factor.

The weakness aligns with [CWE-294], where captured authentication data remains valid outside its intended session. Exploitation depends on the attacker first placing a malicious extension in the victim's browser, which raises complexity but is achievable through supply-chain compromise or social engineering.

Root Cause

The root cause is the absence of adequate replay protection in the authentication workflow. Authentication messages lack strong per-session nonces, cryptographic channel binding, or short-lived tokens that would invalidate captured material after use.

Attack Vector

An attacker first delivers a malicious browser plugin to the victim. Once installed, the plugin inspects the DOM and network traffic generated during login to OpenText Advanced Authentication, capturing the authentication sequence. The attacker then replays the captured sequence from an attacker-controlled context to authenticate as the victim. Refer to the MicroFocus Advanced Authentication Documentation for protocol details.

Detection Methods for CVE-2025-8616

Indicators of Compromise

Authentication events for a single user originating from two distinct client fingerprints within a short window
Successful authentications from IP addresses or user-agent strings that do not match the user's typical baseline
Browser telemetry showing unexpected extensions with permissions to read page content or intercept network requests on the authentication portal

Detection Strategies

Correlate Advanced Authentication server logs with endpoint browser extension inventories to identify sessions produced by unapproved plugins
Alert on repeat authentication payloads or identical session identifiers observed from different sources
Baseline geolocation, ASN, and device attributes for authentication events and flag deviations

Monitoring Recommendations

Ingest Advanced Authentication audit logs into a centralized SIEM for behavioral analytics
Monitor enterprise browsers for newly installed or side-loaded extensions requesting broad host permissions
Track authentication success rates per user and per source to detect anomalous concurrent sessions

How to Mitigate CVE-2025-8616

Immediate Actions Required

Upgrade OpenText Advanced Authentication to a fixed release later than 6.5.0 as provided by the vendor
Enforce browser extension allowlisting through group policy or a managed browser configuration
Review recent authentication logs for signs of replayed sessions and reset credentials for affected users

Patch Information

Refer to the MicroFocus Advanced Authentication Documentation for the vendor-supplied fixed version and upgrade guidance. Apply the vendor patch to all Advanced Authentication server instances at or below version 6.5.0.

Workarounds

Restrict access to the Advanced Authentication portal to managed devices where browser extensions are governed by policy
Shorten authentication session and token lifetimes to reduce the replay window
Require step-up authentication or continuous authorization checks for sensitive downstream applications

bash

# Example managed browser policy fragment to block unapproved extensions
# Chrome/Edge policy: allow only approved extension IDs
ExtensionInstallBlocklist = ["*"]
ExtensionInstallAllowlist = ["<approved_extension_id_1>", "<approved_extension_id_2>"]