CVE-2018-0793 in Word
Summary
by MITRE
Microsoft Outlook 2007, Microsoft Outlook 2010 and Microsoft Outlook 2013 allow a remote code execution vulnerability due to the way email messages are parsed, aka "Microsoft Outlook Remote Code Execution Vulnerability". This CVE is unique from CVE-2018-0791.
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Analysis
by VulDB Data Team • 01/29/2021
The Microsoft Outlook Remote Code Execution Vulnerability CVE-2018-0793 represents a critical security flaw affecting Outlook 2007, 2010, and 2013 versions that stems from improper parsing of email messages. This vulnerability falls under the Common Weakness Enumeration CWE-129 category, which encompasses weaknesses related to improper validation of input boundaries. The flaw specifically manifests when Outlook processes specially crafted email messages containing malformed data structures that trigger unexpected behavior during message parsing operations.
The technical implementation of this vulnerability exploits the way Outlook handles certain email headers and content structures, particularly those involving rich text formatting and embedded objects. When an attacker crafts a malicious email message with carefully constructed payload data, the parsing engine within Outlook fails to properly validate the input, leading to memory corruption that can be leveraged for arbitrary code execution. This issue is particularly dangerous because it operates at the application level parsing stage, meaning that successful exploitation does not require user interaction beyond simply opening the malicious message, though user interaction may still be required for full exploitation.
From an operational impact perspective, this vulnerability presents significant risk to enterprise environments where Outlook is widely deployed as the primary email client. The remote code execution capability allows attackers to execute malicious code with the privileges of the Outlook process, potentially leading to complete system compromise. The vulnerability is particularly concerning because it affects older versions of Outlook that may still be in use within organizations that have not yet migrated to newer versions. Attackers could leverage this vulnerability to establish persistent access, escalate privileges, or deploy additional malware within the network environment. The attack surface is broad as it can be triggered through standard email communication channels, making it a preferred target for phishing campaigns and targeted attacks.
Security mitigations for CVE-2018-0793 should focus on immediate patching of affected Outlook versions, as Microsoft released security updates to address this specific vulnerability. Organizations should implement email filtering solutions that can detect and quarantine suspicious email content, particularly focusing on messages with unusual or malformed headers. Network segmentation and privilege separation can help limit the potential damage from successful exploitation attempts. The vulnerability aligns with ATT&CK technique T1204.002 for 'Exploitation for Execution' and may also map to T1566 for 'Phishing' as the initial delivery mechanism. Additionally, implementing application whitelisting policies and disabling unnecessary email features can provide additional defense in depth. Organizations should also consider monitoring for unusual email processing patterns that might indicate exploitation attempts, particularly around the parsing of rich text content and embedded objects within email messages.