CVE-2017-11774 in Outlook
Summary
by MITRE
Microsoft Outlook 2010 SP2, Outlook 2013 SP1 and RT SP1, and Outlook 2016 allow an attacker to execute arbitrary commands, due to how Microsoft Office handles objects in memory, aka "Microsoft Outlook Security Feature Bypass Vulnerability."
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2017-11774 represents a critical security flaw in Microsoft Outlook versions 2010 SP2, 2013 SP1 and RT SP1, and 2016 that enables remote code execution through improper handling of objects in memory. This vulnerability specifically affects the security feature implementation within Outlook's object model processing mechanisms, creating a pathway for attackers to bypass security controls that are normally in place to prevent malicious code execution. The flaw resides in how Microsoft Office applications manage memory objects during the processing of email messages and attachments, particularly when encountering specially crafted malicious content.
The technical root cause of this vulnerability stems from insufficient validation and sanitization of objects within Outlook's memory management system. When Outlook processes certain email messages containing malformed or specially constructed objects, the application fails to properly validate the integrity of these memory objects before executing operations on them. This improper handling creates an environment where attacker-controlled data can influence the execution flow of the application, potentially allowing arbitrary code execution with the privileges of the logged-on user. The vulnerability is classified as a security feature bypass, meaning it circumvents the intended security protections that should normally prevent such malicious operations from succeeding.
From an operational impact perspective, this vulnerability poses significant risks to enterprise environments where Outlook is widely deployed as the primary email client. Attackers can leverage this flaw by sending malicious email messages to targeted users, which, when opened, trigger the vulnerable code path and enable remote code execution. The attack typically requires social engineering to convince users to open malicious emails, but once executed, the vulnerability allows attackers to install malware, steal credentials, access sensitive data, or establish persistent access to the compromised system. The vulnerability affects both desktop and mobile email clients, making it particularly dangerous in environments where users may access email through multiple device types. This flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how improper memory handling can lead to arbitrary code execution. The vulnerability's exploitation typically follows ATT&CK technique T1204.002, where adversaries attempt to execute malicious code through legitimate user interaction with email messages.
Organizations affected by this vulnerability should implement immediate mitigations including deploying Microsoft security updates, configuring email filtering rules to block suspicious attachments, and implementing user education programs to reduce social engineering success rates. Network segmentation and privilege separation can help limit the potential impact if exploitation occurs. The vulnerability demonstrates the importance of proper input validation and memory management in client-side applications, highlighting how seemingly minor flaws in object handling can result in critical security breaches. Microsoft released security bulletin MS17-059 to address this vulnerability, emphasizing the need for timely patch management and the implementation of layered security controls to protect against similar future exploits.