CVE-2026-48911 in Answer
Summary
by MITRE • 08/05/2026
Insufficient Verification of Data Authenticity vulnerability in Apache Answer.
This issue affects Apache Answer: through 2.0.1.
A missing authorization check in the external-login email binding flow allows unauthenticated attackers to take over arbitrary user accounts by tricking victims into clicking a crafted confirmation link. Users are recommended to upgrade to version 2.0.2, which fixes the issue.
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Analysis
by VulDB Data Team • 08/05/2026
The Insufficient Verification of Data Authenticity vulnerability in Apache Answer represents a critical authorization flaw that undermines the integrity of user account management within the platform. This weakness specifically manifests in the external-login email binding flow where proper authentication checks are absent, creating an exploitable condition that allows malicious actors to hijack user accounts without proper credentials. The vulnerability affects all versions through 2.0.1 and demonstrates a fundamental failure in input validation and user verification processes that should occur during account linking operations.
The technical implementation of this flaw stems from inadequate authorization controls within the email binding mechanism that connects external authentication providers to existing user accounts. When users attempt to bind their external login credentials to an existing account, the system fails to verify that the requester has legitimate authorization to perform this action. This missing validation step creates a path for attackers to craft malicious confirmation links that appear legitimate to unsuspecting victims, enabling unauthorized account takeover through social engineering rather than direct credential compromise.
From an operational perspective, this vulnerability presents significant risk to both individual users and the platform's overall security posture. Attackers can exploit this weakness by generating forged email binding confirmation links that redirect to arbitrary user accounts, potentially gaining access to sensitive personal information, private communications, and platform privileges. The impact extends beyond simple account compromise as it can enable further attacks including data exfiltration, privilege escalation, and potential lateral movement within the system. This vulnerability aligns with CWE-285 which specifically addresses insufficient authorization checks in software systems.
The exploitation of this vulnerability follows a typical social engineering attack pattern where attackers craft deceptive links that appear to be legitimate account binding confirmations. Victims who click these malicious links are unknowingly bound to attacker-controlled accounts, creating persistent access points for further compromise. The attack vector demonstrates the importance of implementing robust input validation and authentication controls at every stage of user interaction, particularly during account linking and verification processes.
Organizations using Apache Answer should immediately implement mitigation strategies including upgrading to version 2.0.2 which addresses this specific authorization flaw through proper validation checks. The fix typically involves implementing additional verification steps that confirm the legitimacy of account binding requests through multiple authentication factors. Security teams should also consider implementing monitoring for suspicious account binding activities and establishing incident response procedures for potential account takeover events. This vulnerability reinforces the ATT&CK technique of credential access through social engineering and account manipulation, emphasizing the need for comprehensive security controls throughout the entire user lifecycle management process.
The broader implications of this vulnerability highlight the critical importance of proper authorization implementation in web applications and demonstrate how seemingly minor validation gaps can create significant security risks. System administrators should conduct thorough security assessments of their Apache Answer installations to ensure all users have been upgraded and that appropriate monitoring has been implemented to detect potential exploitation attempts. The vulnerability serves as a reminder that authentication and authorization controls must be rigorously tested and validated, particularly in multi-factor authentication and account linking scenarios where user trust is paramount.