CVE-2015-6948 in WordPerfect
Summary
by MITRE
Heap-based buffer overflow in the Microsoft Word document conversion feature in Corel WordPerfect allows remote attackers to execute arbitrary code via a crafted document.
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Analysis
by VulDB Data Team • 06/15/2022
The vulnerability identified as CVE-2015-6948 represents a critical heap-based buffer overflow within Microsoft Word document conversion functionality embedded in Corel WordPerfect software. This flaw exists in the processing mechanism that handles document format conversions, specifically when Corel WordPerfect attempts to interpret and transform Microsoft Word documents into its native format. The buffer overflow occurs during the parsing of malformed document structures, creating an exploitable condition that can be leveraged by remote attackers to gain unauthorized code execution privileges on affected systems.
The technical implementation of this vulnerability stems from insufficient input validation and memory management within the document conversion module. When Corel WordPerfect encounters a specially crafted Microsoft Word document containing maliciously constructed data structures, the conversion process fails to properly bounds-check memory allocations. This results in data being written beyond the allocated buffer boundaries, potentially overwriting adjacent memory locations including function pointers, return addresses, or other critical program state information. The flaw falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based and heap-based buffer overflow conditions, and more broadly aligns with CWE-787, which covers out-of-bounds write vulnerabilities.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with a potential pathway for complete system compromise. An attacker can craft a malicious Word document that, when opened or processed by Corel WordPerfect, triggers the buffer overflow condition. This allows for arbitrary code injection with the privileges of the user running the application, potentially enabling privilege escalation, data theft, or establishment of persistent backdoors. The remote attack vector means that exploitation can occur without requiring physical access to the target system, making it particularly dangerous in enterprise environments where document sharing is common. According to the MITRE ATT&CK framework, this vulnerability maps to techniques involving execution through exploitation of remote services and privilege escalation through code injection.
Mitigation strategies for CVE-2015-6948 should encompass multiple defensive layers to protect against exploitation attempts. Organizations should prioritize immediate patch deployment from Corel to address the underlying buffer overflow condition in their WordPerfect software implementations. Additionally, network segmentation and application whitelisting can help limit the potential attack surface by restricting which systems can process untrusted documents. Implementing strict document validation policies, including the use of sandboxed environments for document processing, can provide additional protection layers. Security monitoring should focus on detecting unusual file processing patterns or attempts to execute code within the WordPerfect application context. Regular security assessments and vulnerability scanning should be conducted to identify any potential variants or related vulnerabilities in similar document processing components. The remediation approach must also consider the broader context of document handling security practices within the organization to prevent similar vulnerabilities from emerging in other applications that process similar file formats.