CVE-2016-0794 in LibreOffice
Summary
by MITRE
The lwp filter in LibreOffice before 5.0.4 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a crafted LotusWordPro (lwp) document.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-0794 represents a critical memory corruption flaw within the LotusWordPro (lwp) filter component of LibreOffice versions prior to 5.0.4. This issue resides in the document processing pipeline where LibreOffice handles legacy Lotus Word Pro formatted files, which are commonly encountered in enterprise environments where older document formats persist. The vulnerability is particularly concerning as it demonstrates how legacy format parsers can introduce significant security risks when not properly validated against malicious input. The lwp filter serves as a bridge between the older Lotus Word Pro document format and LibreOffice's native processing capabilities, making it a critical component in the software's document compatibility stack.
The technical flaw manifests through improper input validation and memory handling within the lwp filter implementation. When processing a crafted malicious lwp document, the filter fails to properly sanitize or validate the input structure, leading to memory corruption that can result in arbitrary code execution or complete application crash. This memory corruption occurs during the parsing phase where the filter attempts to interpret the document structure, particularly in handling malformed or specially constructed elements within the lwp format. The vulnerability is categorized under CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1203, which involves exploitation of input validation weaknesses in software applications. The nature of the flaw suggests insufficient bounds checking and memory management practices within the document parser, allowing attackers to manipulate memory layout through carefully crafted document elements.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with potential paths to execute arbitrary code on vulnerable systems. In enterprise environments where LibreOffice serves as a primary office suite, attackers could leverage this vulnerability to compromise user workstations through social engineering campaigns targeting document attachments. The vulnerability affects all versions of LibreOffice prior to 5.0.4, making it particularly dangerous as many organizations maintain older installations due to compatibility requirements or upgrade delays. The memory corruption can manifest in various ways including application crashes, data corruption, or potentially full system compromise if the attacker can achieve code execution in the context of the LibreOffice process. This makes the vulnerability particularly attractive to threat actors targeting office productivity suites, as successful exploitation could provide access to sensitive corporate documents and potentially enable lateral movement within networks.
Mitigation strategies for CVE-2016-0794 primarily focus on immediate software updates to LibreOffice 5.0.4 or later versions where the vulnerability has been addressed through improved input validation and memory management. Organizations should implement comprehensive patch management policies that prioritize security updates for office productivity suites, particularly in environments where legacy document formats are frequently encountered. Network-based mitigations can include filtering of lwp document attachments at email gateways and file transfer points, while endpoint protection solutions should be configured to scan for potentially malicious document files. The vulnerability also underscores the importance of maintaining up-to-date security practices including regular vulnerability assessments and penetration testing of office environments. Additionally, user education regarding the risks of opening unexpected document attachments remains critical, as social engineering often complements technical exploitation attempts in successful attacks against office productivity suites.