libxls vulnerability

[MichaelChirico]

Hi, FYI there's a known vulnerability in libxls v1.6.2:

https://nvd.nist.gov/vuln/detail/CVE-2021-27836

It looks like this upstream PR is the most relevant to consider patching in:

https://github.com/libxls/libxls/pull/97/files

Original upstream discussion: libxls/libxls#94

[stephematician]

FYI: as the original PR was never accepted, I updated the changes and added a PR which has been accepted into the dev branch of libxls - libxls/libxls#107
The changes are largely the same except for error code enumeration.

[MichaelChirico]

Thanks for the heads up! @jennybc would you like me to patch that into the bundled copy here?

[jennybc]

No, I will do it. I've sort of been waiting to see if @evanmiller does an official libxls release, now that it looks like several CVE-relevant PRs have landed.

I much prefer to vendor an official release of libxls, with as few readxl-specific patches as possible.

[jennybc]

Question for those with a particular interest in this:

If I embed the current dev version of libxls in readxl (so: not an official release), instead of the current libxls v1.6.2 (SHA 4482400), is that a noticeably better situation for you?

I plan to release readxl soon. There have been multiple, large internal changes that should not noticeably change what users see. I want to get this next version out into the world and surface any significant regressions. (The next phase of development will introduce quite a few user-significant features.)

[MichaelChirico]

FWIW it doesn't affect us either way. we delete the bundled libxls copy & depend directly on the (patched) source library directly.

[jennybc]

Closed by #721 but I had the wrong issue number there at the time of merge