[
https://issues.apache.org/jira/browse/PDFBOX-4014?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16308928#comment-16308928
]
Jörg Henne commented on PDFBOX-4014:
------------------------------------
I have created a test-case that covers the decoding of the data from
pdfium-loop2.pdf. In order to do so, I've contacted Hanno Böck, the original
author of the pathological PDF document, whether he would agree to the
inclusion of the file under the ASL 2.0. Is it possible to include the file
along with a README along the lines of
{quote}
The file pdfium-loop2.jb2 has been extracted from the file pdfium-loop2.pdf
hosted at
https://bugs.chromium.org/p/chromium/issues/detail?id=450971 (see comment 6).
Permission to use the file under the ASL 2.0 has been granted by its original
author, Hanno Böck.
{quote}
or would we have to go through the whole ICLA process?
> Malformed/pathological/malicious input can lead to infinite looping
> -------------------------------------------------------------------
>
> Key: PDFBOX-4014
> URL: https://issues.apache.org/jira/browse/PDFBOX-4014
> Project: PDFBox
> Issue Type: Bug
> Components: JBIG2
> Affects Versions: 3.0.0 JBIG2
> Reporter: Jörg Henne
> Assignee: Jörg Henne
>
> [~tilman] writes
> {quote}
> See this issue:
> https://bugs.chromium.org/p/chromium/issues/detail?id=450971
> look for "pdfium-loop2.pdf".
> I haven't created an issue, because this could be relevant to security.
> To reproduce the bug with PDFBox, do this:
> PDDocument document = PDDocument.load(new
> File("pdfium-loop2.pdf"));
> new PDFRenderer(document).renderImage(0);
> For maven you need
> <dependency>
> <groupId>org.apache.pdfbox</groupId>
> <artifactId>pdfbox</artifactId>
> <version>2.0.8</version>
> </dependency>
> and of course jbig2.
> {quote}
> An analysis shows that two circumstances contribute to the problem:
> # T.88 section E.2.10 specifies that MQ encoded data can be minimized if
> trailing data contains "just boring stuff, i.e. 1-bits". Thus, an infinite
> sequence of MQ encoded decisions can be encoded in a finite number of bytes.
> # T.88 section 6.4.5 3c specifies that the condition for terminating the
> decoding of a text region strip is the occurrence of the OOB symbol as a
> symbol's S coordinate.
> If a JBIG2 stream contains a strip that uses #1 yielding a stream of S
> coordinates that never contain OOB during the decoding phase for #2, an
> infinite loop results, as text region decoding has no other terminating
> condition.
> The result is "just" a denial of service. No risk of buffer overruns etc. is
> associated with the issue.
> A similar issue exists with symbol dictionary decoding. However in this case
> decoding will not enter an infinite loop due to an array index out of bounds
> exception that is thrown once more symbols than expected have been decoded.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
