CVE-2018-4001 in Word Processor
Summary
by MITRE
An exploitable uninitialized pointer vulnerability exists in the Office Open XML parser of Atlantis Word Processor, version 3.2.5.0. A specially crafted document can cause an uninitialized pointer representing a TTableRow to be assigned to a variable on the stack. This variable is later dereferenced and then written to allow for controlled heap corruption, which can lead to code execution under the context of the application. An attacker must convince a victim to open a document in order to trigger this vulnerability.
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Analysis
by VulDB Data Team • 05/19/2023
The vulnerability identified as CVE-2018-4001 represents a critical uninitialized pointer flaw within the Office Open XML parser implementation of Atlantis Word Processor version 3.2.5.0. This type of vulnerability falls under the CWE-457 category of "Use of Uninitialized Variable" and demonstrates a classic memory safety issue that can be exploited to achieve arbitrary code execution. The flaw specifically manifests when processing specially crafted Office Open XML documents, making it particularly dangerous in environments where users frequently handle document attachments from untrusted sources.
The technical exploitation mechanism involves the parser's handling of TTableRow objects within the document structure. When processing malformed documents, the parser fails to properly initialize a pointer variable that should represent a table row object. This uninitialized pointer is subsequently assigned to a stack variable and later dereferenced during the document processing flow. The vulnerability's design allows for controlled heap corruption through subsequent write operations to the uninitialized memory location, creating a predictable exploitation path that can be leveraged by malicious actors to execute arbitrary code within the application's security context.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables full code execution capabilities under the privileges of the Atlantis Word Processor application. This means that successful exploitation could allow attackers to execute malicious code, install malware, modify or delete files, and potentially establish persistent access to affected systems. The attack vector requires social engineering to convince victims to open the malicious document, making it particularly challenging to defend against in enterprise environments where document sharing is common. The vulnerability affects the application's document parsing functionality and could be exploited in targeted attacks against specific users or organizations that rely on Atlantis Word Processor for document handling.
Security mitigations for this vulnerability should focus on immediate patching of the Atlantis Word Processor application to version 3.2.5.1 or later, which contains the necessary fixes for the uninitialized pointer handling. Organizations should also implement document sanitization policies that scan and validate all incoming Office Open XML documents before processing. Network-based protections such as email filtering and web application firewalls can help prevent delivery of malicious documents to users. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1204.002 for "Exploitation for Execution" and demonstrates the importance of memory safety practices in document processing applications. The vulnerability highlights the need for robust input validation and proper initialization of all variables in parsing libraries, particularly those handling complex document formats that are commonly targeted by attackers due to their widespread use and potential for privilege escalation.