CVE-2021-32665 in Wire
Summary
by MITRE • 06/04/2021
wire-ios is the iOS version of Wire, an open-source secure messaging app. wire-ios versions 3.8.0 and earlier have a bug in which a conversation could be incorrectly set to "unverified. This occurs when: - Self user is added to a new conversation - Self user is added to an existing conversation - All the participants in the conversation were previously marked as verified. The vulnerability is patched in wire-ios version 3.8.1. As a workaround, one can unverify & verify a device in the conversation.
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Analysis
by VulDB Data Team • 06/07/2021
The vulnerability identified as CVE-2021-32665 affects wire-ios, the iOS implementation of the Wire secure messaging platform, specifically versions 3.8.0 and earlier. This security flaw represents a significant issue in the application's verification system, which is critical for maintaining end-to-end encryption integrity and user trust within secure communications. The vulnerability stems from improper handling of conversation verification states when users are added to conversations, creating a potential attack vector that could compromise the security posture of encrypted communications.
The technical flaw manifests when a user is added to either a new or existing conversation where all participants were previously marked as verified. Under these specific conditions, the application incorrectly sets the conversation to an "unverified" state despite the presence of only verified participants. This represents a failure in the application's state management and verification logic, where the system does not properly account for the existing verification status of participants when processing new user additions. The issue falls under CWE-284, Access Control, as it involves improper handling of access control states within the verification system, and may also relate to CWE-345 Insufficient Verification of Data Authenticity, given the incorrect verification state propagation.
The operational impact of this vulnerability extends beyond simple user experience issues to potentially compromise the security of encrypted communications. When a conversation is incorrectly marked as unverified, users may be misled into believing that their communications are at risk, potentially causing unnecessary alarm and prompting users to take defensive actions that could disrupt normal communication workflows. More critically, this could create a false sense of security where users might not notice actual threats to their verification status, as the system's verification state becomes unreliable. The vulnerability specifically impacts the trust model of the Wire platform, where verification status is fundamental to maintaining secure communication channels.
The patch released in wire-ios version 3.8.1 addresses this issue by correcting the verification state logic during user addition scenarios. The workaround provided by the vendor, which involves unverifying and re-verifying a device within the conversation, serves as a temporary mitigation strategy but does not address the underlying state management flaw. This vulnerability demonstrates the importance of proper state synchronization in cryptographic systems and highlights the need for comprehensive testing of edge cases in verification workflows. Organizations should consider implementing monitoring for unusual verification state changes and ensure timely patch deployment to maintain the security integrity of their secure communication platforms. The incident also underscores the necessity of following ATT&CK framework principles for secure communication systems, particularly in maintaining proper verification states and preventing false security alerts that could lead to user confusion and potential security gaps.