A flaw was found in the way the Git client handles "ssh://" URLs. A maliciously crafted "ssh://" URL would cause Git clients to run an arbitrary shell command. Such a URL could be generated by a malicious server, by a malicious users committing to an honest server (to attack another user of that server's repositories), or by a proxy server.
External References: https://lkml.org/lkml/2017/8/10/757 http://blog.recurity-labs.com/2017-08-10/scm-vulns
Updates for Fedora 25 and 26 were pushed while this bug was being created. I don't see any Fedora tracker bugs. For Fedora users who search by the CVE and want to find the updates for testing, here are the links: https://bodhi.fedoraproject.org/updates/FEDORA-2017-b1b3ae6666 https://bodhi.fedoraproject.org/updates/FEDORA-2017-8ba7572cfd
git-2.13.5-1.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.
git-2.9.5-1.fc25 has been pushed to the Fedora 25 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:2484 https://access.redhat.com/errata/RHSA-2017:2484
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2017:2485 https://access.redhat.com/errata/RHSA-2017:2485
This issue has been addressed in the following products: Red Hat Software Collections for Red Hat Enterprise Linux 6 Red Hat Software Collections for Red Hat Enterprise Linux 7 Via RHSA-2017:2491 https://access.redhat.com/errata/RHSA-2017:2491
This issue has been addressed in the following products: Red Hat Mobile Application Platform 4.5 Via RHSA-2017:2675 https://access.redhat.com/errata/RHSA-2017:2675
This issue has been addressed in the following products: Red Hat Mobile Application Platform 4.5 Via RHSA-2017:2674 https://access.redhat.com/errata/RHSA-2017:2674