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<p>Hi,</p>
<p>TLDR: no specific reason to worry.</p>
<p>My longer analysis:<br>
</p>
<p>Those following the recent security news have certainly come
across <a class="moz-txt-link-freetext" href="https://lwn.net/Articles/967180">https://lwn.net/Articles/967180</a> or similar articles, and if
you don't have and have been running a cutting edge Linux
distribution recently, you *should* follow related security alerts
emitted by your vendor.</p>
<p>liblzma (the library part of the xz software distribution) is an
optional libtiff dependency for the TIFF LZMA codec, and an
optional direct GDAL dependency since GDAL 1.8.0. Initially only
used when building GDAL with its internal libtiff, and since GDAL
3.4.0, directly too as a Zarr codec.<br>
</p>
<p>Beyond activity in liblzma / xz being potentially suspicious with
at least 2 years of "contributions" by malicious actor
<a class="moz-txt-link-freetext" href="https://github.com/JiaT75">https://github.com/JiaT75</a><span class="commtext c00">, which makes
the current headlines, it has also been found that they
contributed to libarchive too since 2021
(<a class="moz-txt-link-freetext" href="https://github.com/libarchive/libarchive/commits?author=JiaT75">https://github.com/libarchive/libarchive/commits?author=JiaT75</a>),
and their latest commit
<a class="moz-txt-link-freetext" href="https://github.com/libarchive/libarchive/pull/1609">https://github.com/libarchive/libarchive/pull/1609</a> is in
particular pointed as suspicious. As far as I can see, this
commit is present in libarchive >= 3.6. I mention libarchive
because it is an optional GDAL dependency since GDAL 3.7.0 for
the /vsi7z/ and /vsirar/ virtual file systems. <br>
</span></p>
<p><span class="commtext c00">We don't have vendored copies of
liblzma or libarchive in the GDAL source code repository.<br>
</span></p>
<p>Regarding GDAL Docker images, here's the status of versions they
ship:<br>
</p>
<p>- ghcr.io/osgeo/gdal:alpine-small-3.8.4 and
ghcr.io/osgeo/gdal:alpine-normal-3.8.4:<br>
xz-libs-5.4.3-r0 <br>
libarchive-3.7.2-r0<br>
</p>
<p>- ghcr.io/osgeo/gdal:ubuntu-full-3.8.4:<br>
liblzma5:amd64 5.2.5-2ubuntu1 <br>
libarchive13:amd64 3.6.0-1ubuntu1<br>
</p>
<p>- ghcr.io/osgeo/gdal:ubuntu-small-3.8.4:<br>
liblzma5:amd64 5.2.5-2ubuntu1<br>
</p>
<p>So those liblzma versions are not currently considered as
affected. Regarding libarchive status and the impact of JiaT75's
activity there, it seems to me we are yet in undecided territory
and it wouldn't be surprising to see update of those libraries in
the coming weeks, as exploration of past activity from that
compromising entity is performed.<br>
</p>
<p>It is a good time to recall usual general best-practices:<br>
</p>
<p>- avoid opening datasets coming from unknown or untrusted sources<br>
</p>
<p>- if you do so, prefer doing that on dedicated workstations that
don't have access to sensitive information<br>
</p>
<p>- you may reduce your potential exposure by disabling at build
time optional dependencies you don't need.</p>
<p>Even<br>
</p>
<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-freetext" href="http://www.spatialys.com">http://www.spatialys.com</a>
My software is free, but my time generally not.</pre>
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