Public bug reported:

Notes:

* I am the upstream author and debian maintainer for qpdf.
* This bug has been fixed in debian unstable and testing with version 11.6.3, 
but because 24.04 is not yet open, it has not synced. This should not block 
fixing 23.04 and 22.04. I have uploaded 11.6.3 to my ppa: 
https://launchpad.net/~qpdf/+archive/ubuntu/qpdf
* I am attaching debdiffs for lunar and mantic

Upstream bug https://github.com/qpdf/qpdf/issues/1050 revealed a bug in
qpdf's lexical layer that would cause qpdf to discard the character in a
binary string following an octal quoted character with 1 or 2 digits.
The PDF spec allows octal digits to be \d, \dd, or \ddd, and allows the
first two forms if the next character is other than an octal digit. Most
PDF writers never use the \d or \dd forms, but some do. With default
options, qpdf does not parse or alter strings inside content streams, so
this bug is not likely to affect page content. However, binary strings
of this sort are common in the document /ID and may also appear in
metadata for encrypted files. In some cases, such as the file in #1050,
this bug can cause error, in this case, because the discarded character
was the string end delimiter. In most case, this bug results in silent
data loss. The fix is very small and locally contained. The upstream fix
includes several new test cases, but the patch I will include to fix the
issue only includes the relevant code change.

I also reported this as a debian bug: https://bugs.debian.org/cgi-
bin/bugreport.cgi?bug=1054158

It was approved as a stable update by debian:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054119

[ Impact ]

The bug could result in silent corruption of binary strings in PDF
metadata. It could also result in failure of qpdf to process a valid
file. Data loss justifies a stable update.

[ Test Plan ]

The test file in https://github.com/qpdf/qpdf/issues/1050 can be used to
prove that the bug exists in versions >= 11.0.0 and <= 11.6.2 and that
the bug is fixed in 11.6.3.

The upstream fix includes several additional automated test cases. These
are not included in the patch, but they are included in the upstream
commit that fixes the bug:
https://github.com/qpdf/qpdf/commit/1ecc6bb29e24a4f89470ff91b2682b46e0576ad4

[ Where problems could occur ]

This fix has a very low risk of causing a regression. The fix is very
localized to qpdf's lexical layer and is in a code path that only occurs
when a 1-digit or 2-digit octal quoted character is terminated by other
than an octal digit. This is the first bug in qpdf's lexical layer in
many years. It was introduced by a pull request from a reliable and
consistent contributor who has made may improvements to qpdf's
performance. The fix follows the established pattern of how to handle
instances in which a character triggers a state change and has to be
reprocessed in the new state.

qpdf has a rigorous test suite and an extremely good quality record. It
processes millions of documents daily by many commercial entities. My
current employer runs millions of pages a day through qpdf.

[ Other Info ]

See also

Upstream bug report: https://github.com/qpdf/qpdf/issues/1050
Corresponding debian bug report: 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054158
Debian stable release approval: 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054119

** Affects: qpdf (Ubuntu)
     Importance: Undecided
         Status: New

** Patch added: "qpdf-11.3.0-1ubuntu1.debdiff"
   
https://bugs.launchpad.net/bugs/2039804/+attachment/5711201/+files/qpdf-11.3.0-1ubuntu1.debdiff

-- 
You received this bug notification because you are a member of Desktop
Packages, which is subscribed to qpdf in Ubuntu.
https://bugs.launchpad.net/bugs/2039804

Title:
  SRU request: qpdf: data loss bug affecting versions 11.0.0 through
  11.6.2

Status in qpdf package in Ubuntu:
  New

Bug description:
  Notes:

  * I am the upstream author and debian maintainer for qpdf.
  * This bug has been fixed in debian unstable and testing with version 11.6.3, 
but because 24.04 is not yet open, it has not synced. This should not block 
fixing 23.04 and 22.04. I have uploaded 11.6.3 to my ppa: 
https://launchpad.net/~qpdf/+archive/ubuntu/qpdf
  * I am attaching debdiffs for lunar and mantic

  Upstream bug https://github.com/qpdf/qpdf/issues/1050 revealed a bug
  in qpdf's lexical layer that would cause qpdf to discard the character
  in a binary string following an octal quoted character with 1 or 2
  digits. The PDF spec allows octal digits to be \d, \dd, or \ddd, and
  allows the first two forms if the next character is other than an
  octal digit. Most PDF writers never use the \d or \dd forms, but some
  do. With default options, qpdf does not parse or alter strings inside
  content streams, so this bug is not likely to affect page content.
  However, binary strings of this sort are common in the document /ID
  and may also appear in metadata for encrypted files. In some cases,
  such as the file in #1050, this bug can cause error, in this case,
  because the discarded character was the string end delimiter. In most
  case, this bug results in silent data loss. The fix is very small and
  locally contained. The upstream fix includes several new test cases,
  but the patch I will include to fix the issue only includes the
  relevant code change.

  I also reported this as a debian bug: https://bugs.debian.org/cgi-
  bin/bugreport.cgi?bug=1054158

  It was approved as a stable update by debian:
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054119

  [ Impact ]

  The bug could result in silent corruption of binary strings in PDF
  metadata. It could also result in failure of qpdf to process a valid
  file. Data loss justifies a stable update.

  [ Test Plan ]

  The test file in https://github.com/qpdf/qpdf/issues/1050 can be used
  to prove that the bug exists in versions >= 11.0.0 and <= 11.6.2 and
  that the bug is fixed in 11.6.3.

  The upstream fix includes several additional automated test cases.
  These are not included in the patch, but they are included in the
  upstream commit that fixes the bug:
  https://github.com/qpdf/qpdf/commit/1ecc6bb29e24a4f89470ff91b2682b46e0576ad4

  [ Where problems could occur ]

  This fix has a very low risk of causing a regression. The fix is very
  localized to qpdf's lexical layer and is in a code path that only
  occurs when a 1-digit or 2-digit octal quoted character is terminated
  by other than an octal digit. This is the first bug in qpdf's lexical
  layer in many years. It was introduced by a pull request from a
  reliable and consistent contributor who has made may improvements to
  qpdf's performance. The fix follows the established pattern of how to
  handle instances in which a character triggers a state change and has
  to be reprocessed in the new state.

  qpdf has a rigorous test suite and an extremely good quality record.
  It processes millions of documents daily by many commercial entities.
  My current employer runs millions of pages a day through qpdf.

  [ Other Info ]

  See also

  Upstream bug report: https://github.com/qpdf/qpdf/issues/1050
  Corresponding debian bug report: 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054158
  Debian stable release approval: 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054119

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