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Guard Ole10Native readUtf16 byte length against int overflow #1080

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Guard Ole10Native readUtf16 byte length against int overflow #1080

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2 changes: 1 addition & 1 deletion poi/src/main/java/org/apache/poi/poifs/filesystem/Ole10Native.java
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Original file line number Diff line number Diff line change
Expand Up @@ -290,7 +290,7 @@ private static String readAsciiLen(LittleEndianByteArrayInputStream leis) throws

private static String readUtf16(LittleEndianByteArrayInputStream leis) throws IOException {
int size = leis.readInt();
byte[] buf = IOUtils.toByteArray(leis, size * 2, MAX_STRING_LENGTH);
byte[] buf = IOUtils.toByteArray(leis, size * 2L, MAX_STRING_LENGTH);
return StringUtil.getFromUnicodeLE(buf, 0, size);
}

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20 changes: 20 additions & 0 deletions poi/src/test/java/org/apache/poi/poifs/filesystem/TestOle10Native.java
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Expand Up @@ -33,6 +33,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
import org.apache.poi.POIDataSamples;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.RecordFormatException;
import org.junit.jupiter.api.Test;

Expand Down Expand Up @@ -107,4 +108,23 @@ void testOleNativeOOM() throws IOException {
}
}

@Test
void testOle10NativeUtf16SizeOverflow() {
// command2 declares 0x40000001 UTF-16 chars; the byte count (size * 2) overflows
// a signed int to a negative value that slips past the MAX_STRING_LENGTH cap.
byte[] data = new byte[34];
LittleEndian.putShort(data, 4, (short) 2); // flags1 -> parsed encoding
data[6] = 'A'; // label (AsciiZ)
data[8] = 'B'; // fileName (AsciiZ)
// flags2, unknown1, ascii command length and data length stay zero
LittleEndian.putInt(data, 22, 0x40000001); // command2 char count
LittleEndian.putInt(data, 0, data.length - 4); // totalSize

RecordFormatException ex = assertThrows(
RecordFormatException.class,
() -> new Ole10Native(data, 0)
);
assertTrue(ex.getMessage().contains("Tried to allocate"));
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@pjfanning pjfanning May 25, 2026

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Use POITestCase assertContains

}

}