CVE-2024-38197 in Teams
Summary
by MITRE • 08/13/2024
Microsoft Teams for iOS Spoofing Vulnerability
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Analysis
by VulDB Data Team • 06/27/2026
Microsoft Teams for iOS suffers from a spoofing vulnerability that allows attackers to manipulate the display of user identities and messages within the mobile application. This flaw stems from insufficient input validation and sanitization mechanisms that process user-generated content and identity information. The vulnerability specifically affects how the iOS client renders sender names, profile pictures, and message metadata, creating opportunities for malicious actors to present false information to other users in the chat environment.
The technical implementation of this vulnerability involves improper handling of user-provided data during message rendering and display operations within the Teams mobile application. Attackers can craft specially formatted messages or manipulate existing data structures to cause the client to display misleading identity information, potentially impersonating legitimate users or organizations. This issue primarily manifests when the application processes rich text content, emoji sequences, or Unicode characters that can be manipulated to alter how names and avatars appear to end users.
The operational impact of this vulnerability extends beyond simple identity confusion, as it can enable more sophisticated attacks such as social engineering campaigns, phishing attempts, and credential harvesting operations. Users may be deceived into trusting malicious communications from apparently legitimate sources, potentially leading to unauthorized access to sensitive information or systems. The vulnerability is particularly concerning in enterprise environments where Teams serves as a primary communication platform for business-critical discussions and collaborations.
Security researchers have identified this issue as corresponding to CWE-20, which addresses improper input validation in software applications. The vulnerability also maps to several ATT&CK techniques including T1566 for phishing campaigns and T1078 for valid accounts usage. Organizations should consider implementing network-level monitoring to detect unusual message patterns or identity manipulations that might indicate exploitation attempts. The risk is amplified when considering the widespread adoption of Teams across enterprise environments where users may be less cautious about verifying identity information in mobile applications.
Mitigation strategies should include immediate deployment of Microsoft's security patches and updates for Teams iOS clients, along with enhanced monitoring of suspicious messaging patterns within Teams environments. Organizations should also implement additional verification mechanisms for critical communications, such as requiring multi-factor authentication for sensitive operations and establishing clear protocols for validating user identities. Network administrators should consider deploying intrusion detection systems that can identify potential exploitation attempts through unusual message formatting or identity manipulation patterns. Regular security awareness training for users about the risks of accepting suspicious communications is essential to reduce the overall attack surface.
The vulnerability demonstrates the importance of proper input sanitization in mobile applications and highlights the challenges of maintaining security in complex communication platforms. Organizations should conduct thorough security assessments of their mobile application usage, particularly focusing on how user-generated content is processed and displayed. Implementing robust logging and monitoring capabilities for Teams activities can help detect exploitation attempts before they cause significant damage to organizational security posture. Additionally, regular vulnerability assessments and penetration testing of mobile applications should be part of comprehensive cybersecurity programs to identify similar issues before they can be exploited by malicious actors.