Improper Input Validation vulnerability in Apache POI. The issue affects the parsing of OOXML format files like xlsx, docx and pptx. These file formats are basically zip files and it is possible for malicious users to add zip entries with duplicate names (including the path) in the zip. In this case, products reading the affected file could read different data because 1 of the zip entries with the duplicate name is selected over another but different products may choose a different zip entry.
This issue affects Apache POI poi-ooxml before 5.4.0. poi-ooxml 5.4.0 has a check that throws an exception if zip entries with duplicate file names are found in the input file.
Users are recommended to upgrade to version poi-ooxml 5.4.0, which fixes the issue. Please read https://poi.apache.org/security.html for recommendations about how to use the POI libraries securely.
A shortcoming in the HMEF package of poi-scratchpad (Apache POI) allows an attacker to cause an Out of Memory exception. This package is used to read TNEF files (Microsoft Outlook and Microsoft Exchange Server). If an application uses poi-scratchpad to parse TNEF files and the application allows untrusted users to supply them, then a carefully crafted file can cause an Out of Memory exception. This issue affects poi-scratchpad version 5.2.0 and prior versions. Users are recommended to upgrade to poi-scratchpad 5.2.1.
In Apache POI up to 4.1.0, when using the tool XSSFExportToXml to convert user-provided Microsoft Excel documents, a specially crafted document can allow an attacker to read files from the local filesystem or from internal network resources via XML External Entity (XXE) Processing.
Apache POI in versions prior to release 3.17 are vulnerable to Denial of Service Attacks: 1) Infinite Loops while parsing crafted WMF, EMF, MSG and macros (POI bugs 61338 and 61294), and 2) Out of Memory Exceptions while parsing crafted DOC, PPT and XLS (POI bugs 52372 and 61295).
Apache POI in versions prior to release 3.15 allows remote attackers to cause a denial of service (CPU consumption) via a specially crafted OOXML file, aka an XML Entity Expansion (XEE) attack.
The XLSX2CSV example in Apache POI before 3.14 allows remote attackers to read arbitrary files via a crafted OpenXML document containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.
Apache POI before 3.10.1 and 3.11.x before 3.11-beta2 allows remote attackers to cause a denial of service (CPU consumption and crash) via a crafted OOXML file, aka an XML Entity Expansion (XEE) attack.