CVE-2018-1028 in Office
Summary
by MITRE
A remote code execution vulnerability exists when the Office graphics component improperly handles specially crafted embedded fonts, aka "Microsoft Office Graphics Remote Code Execution Vulnerability." This affects Word, Microsoft Office, Microsoft SharePoint, Excel, Microsoft SharePoint Server.
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Analysis
by VulDB Data Team • 02/09/2021
The vulnerability identified as CVE-2018-1028 represents a critical remote code execution flaw within Microsoft Office's graphics component that specifically manifests when processing embedded fonts. This weakness resides in how Office applications handle specially crafted font files, creating a pathway for attackers to execute arbitrary code on affected systems. The vulnerability impacts multiple Microsoft Office products including Word, Excel, and SharePoint Server, making it particularly dangerous due to the widespread use of these applications in enterprise environments. The flaw is classified as a remote code execution vulnerability under CWE-119 which addresses weaknesses in memory handling and data processing that can lead to arbitrary code execution. This vulnerability is particularly concerning because it can be exploited through malicious documents or files hosted on SharePoint servers, allowing attackers to gain unauthorized access to systems without requiring user interaction beyond opening the compromised file.
The technical exploitation of this vulnerability occurs through the improper handling of embedded font data within Office documents, specifically when the graphics component processes font files that contain malicious code. When a user opens a specially crafted document containing malicious embedded fonts, the Office application's graphics engine attempts to render these fonts, triggering the vulnerability. This flaw operates at the intersection of memory corruption and code execution, allowing attackers to inject and run malicious code within the context of the Office application process. The vulnerability is particularly dangerous because it can be triggered through various attack vectors including email attachments, web downloads, or SharePoint document libraries. The exploitation mechanism aligns with ATT&CK technique T1203 which describes the use of malicious documents to gain initial access to target systems, while also potentially enabling privilege escalation through code execution in the application context.
The operational impact of CVE-2018-1028 extends beyond individual system compromise to potentially affect entire enterprise networks, as Office applications are extensively used across organizations. Attackers can leverage this vulnerability to establish persistent access, deploy additional malware, or escalate privileges to gain administrative control over affected systems. The vulnerability's presence in SharePoint Server components particularly increases risk for organizations relying on SharePoint for document management and collaboration, as attackers can compromise the entire SharePoint infrastructure. Organizations may experience significant downtime, data breaches, and potential regulatory compliance issues if exploited successfully. The vulnerability's exploitation requires minimal user interaction beyond opening a malicious document, making it particularly effective for phishing campaigns and social engineering attacks. Security teams must consider the potential for lateral movement within networks once initial compromise occurs, as the executed code operates with the privileges of the Office application process. The impact is further amplified by the fact that many organizations have legacy systems that may not have received timely security updates, leaving them vulnerable to exploitation.
Mitigation strategies for CVE-2018-1028 should prioritize immediate patch management with Microsoft security updates, as the vulnerability was addressed through official Microsoft patches released in October 2018. Organizations should implement strict document filtering policies to prevent execution of potentially malicious Office documents, particularly those containing embedded fonts from untrusted sources. Network segmentation and application whitelisting can help reduce the attack surface by limiting which systems can process Office documents. Security monitoring should focus on detecting unusual Office application behavior, including unexpected network connections or file access patterns that may indicate exploitation attempts. Email security solutions should be configured to scan and block suspicious Office documents, particularly those with embedded fonts or macros. Regular security awareness training for users can help reduce the risk of successful exploitation through phishing attacks. System administrators should consider disabling embedded font processing in Office applications where possible, though this may impact legitimate functionality. The vulnerability's classification under CWE-119 and its exploitation patterns align with common security controls recommended for memory corruption vulnerabilities, emphasizing the importance of exploit prevention mechanisms and regular system updates to maintain protection against similar threats.