CVE-2023-35947

Gradle is a build tool with a focus on build automation and support for
multi-language development. In affected versions when unpacking Tar
archives, Gradle did not check that files could be written outside of the
unpack location. This could lead to important files being overwritten
anywhere the Gradle process has write permissions. For a build reading Tar
entries from a Tar archive, this issue could allow Gradle to disclose
information from sensitive files through an arbitrary file read. To exploit
this behavior, an attacker needs to either control the source of an archive
already used by the build or modify the build to interact with a malicious
archive. It is unlikely that this would go unnoticed. A fix has been
released in Gradle 7.6.2 and 8.2 to protect against this vulnerability.
Starting from these versions, Gradle will refuse to handle Tar archives
which contain path traversal elements in a Tar entry name. Users are
advised to upgrade. There are no known workarounds for this vulnerability.

Impact This is a path traversal vulnerability when Gradle deals with

Tar archives, often referenced as TarSlip, a variant of ZipSlip. * When
unpacking Tar archives, Gradle did not check that files could be written
outside of the unpack location. This could lead to important files being
overwritten anywhere the Gradle process has write permissions. * For a
build reading Tar entries from a Tar archive, this issue could allow Gradle
to disclose information from sensitive files through an arbitrary file
read. To exploit this behavior, an attacker needs to either control the
source of an archive already used by the build or modify the build to
interact with a malicious archive. It is unlikely that this would go
unnoticed. Gradle uses Tar archives for its Build
Cache. These
archives are safe when created by Gradle. But if an attacker had control of
a remote build cache server, they could inject malicious build cache
entries that leverage this vulnerability. This attack vector could also be
exploited if a man-in-the-middle can be performed between the remote cache
and the build. ### Patches A fix has been released in Gradle 7.6.2 and 8.2
to protect against this vulnerability. Starting from these versions, Gradle
will refuse to handle Tar archives which contain path traversal elements in
a Tar entry name. It is recommended that users upgrade to a patched
version. ### Workarounds There is no workaround. * If your build deals with
Tar archives that you do not fully trust, you need to inspect them to
confirm they do not attempt to leverage this vulnerability. * If you use
the Gradle remote build cache, make sure only trusted parties have write
access to it and that connections to the remote cache are properly secured.

References * [CWE-22: Improper Limitation of a Pathname to a Restricted

Directory (‘Path
Traversal’)](https://cwe.mitre.org/data/definitions/22.html) * Gradle
Build Cache *
ZipSlip