CVE-2019-1105 in Outlook
Summary
by MITRE
A spoofing vulnerability exists in the way Microsoft Outlook for Android software parses specifically crafted email messages, aka 'Outlook for Android Spoofing Vulnerability'.
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Analysis
by VulDB Data Team • 11/13/2023
The CVE-2019-1105 vulnerability represents a significant spoofing flaw in Microsoft Outlook for Android that exploits the application's email parsing mechanisms to deceive users about the authenticity of incoming messages. This vulnerability specifically targets the email client's handling of specially crafted email headers and content structures that can manipulate how the application displays sender information and message attributes. The flaw resides in the client-side parsing logic that fails to properly validate or sanitize email message components before rendering them to the user interface, creating an avenue for malicious actors to present misleading information about email origins and identities. This issue affects the fundamental trust model of email communication within the Android mobile platform, where users rely on visual indicators and header information to verify message authenticity.
The technical implementation of this vulnerability stems from improper input validation within the Outlook for Android application's email processing pipeline. When the application encounters malformed or specially constructed email messages, it fails to perform adequate sanitization of header fields such as From, Reply-To, and Sender addresses. This parsing deficiency allows attackers to craft emails that appear to originate from legitimate sources while actually containing malicious payloads or phishing content. The vulnerability operates at the application layer where email clients interpret and display message metadata, making it particularly dangerous because it bypasses traditional email security mechanisms that operate at the server level. According to CWE classification, this represents a weakness in input validation and sanitization, specifically categorized under CWE-20: Improper Input Validation, which directly enables various spoofing attacks and social engineering campaigns.
The operational impact of CVE-2019-1105 extends beyond simple message misrepresentation to create substantial security risks for mobile email users. Attackers can exploit this vulnerability to conduct sophisticated phishing campaigns by making malicious emails appear to originate from trusted contacts, organizations, or service providers. The vulnerability enables man-in-the-middle attacks where users are deceived into believing they are interacting with legitimate communications while actually engaging with malicious content. Mobile users are particularly susceptible due to the limited visual cues available on small screens and the trust users place in their email applications. This vulnerability aligns with ATT&CK technique T1566.001: Phishing for Information, where adversaries leverage spoofed email content to harvest credentials and sensitive information from victims. The risk is compounded by the fact that users may not notice the spoofing until after they have interacted with the malicious content, potentially leading to account compromises, data breaches, or financial fraud.
Mitigation strategies for CVE-2019-1105 require both immediate patching and operational security enhancements. Microsoft released security updates addressing this vulnerability through regular patch management procedures, emphasizing the importance of timely software updates for mobile email clients. Organizations should implement comprehensive email security solutions including advanced threat protection, email filtering, and user education programs to reduce the effectiveness of spoofing attacks. Security teams should conduct regular vulnerability assessments of mobile email applications and establish monitoring procedures to detect unusual email patterns that might indicate spoofing attempts. The remediation process involves not only applying the vendor-provided patches but also implementing additional layers of email validation including DMARC, SPF, and DKIM checks. Network administrators should consider deploying email security gateways that can identify and quarantine suspicious email patterns before they reach mobile devices, while users should be trained to verify sender information through multiple channels and avoid clicking on suspicious links or attachments. This vulnerability demonstrates the critical importance of mobile email security and the need for robust client-side validation mechanisms that protect users from sophisticated social engineering attacks.