[TIKA-2446] Tainted Zip file can provoke OOM errors

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16
• Fix Version/s: 1.19, 2.0.0
• Assignee: Unassigned
• Reporter: Thorsten Schäfer
• Created: 24/Aug/17 07:35
• Updated: 07/Jun/18 05:03
• Resolved: 06/Jun/18 19:36

Description

Hi,

using Tika 1.16 with embedded POI 3.17-beta1 we experienced an OutOfMemory error on a Zip file. The suspicious code is in the constructor of FakeZipEntry in line 125. Here a ByteArrayOutputStream of up to 2 GiB in size is opened which will most probably lead to an OutOfMemory. The entry size in the zip file can be easily faked by an attacker.

The code path to FakeZipEntry will be used only if the native java.util.zip.ZipFile implementation already failed to open the (possibly corrupted) Zip. Possibly a more fine grained error analysis could be done in ZipPackage.

I have attached a tweaked zip file that will provoke this error.

public FakeZipEntry(ZipEntry entry, InputStream inp) throws IOException {
			super(entry.getName());
			
			// Grab the de-compressed contents for later
            ByteArrayOutputStream baos;

            long entrySize = entry.getSize();

            if (entrySize !=-1) {
                if (entrySize>=Integer.MAX_VALUE) {
                    throw new IOException("ZIP entry size is too large");
                }

                baos = new ByteArrayOutputStream((int) entrySize);
            } else {
    			baos = new ByteArrayOutputStream();
            }

Kinds,

Thorsten