The git_oid_nfmt function in commit.c in libgit2 before 0.24.3 allows remote attackers to cause a denial of service (NULL pointer dereference) via a cat-file command with a crafted object file.
https://github.com/libgit2/libgit2/releases/tag/v0.24.3
https://github.com/libgit2/libgit2/issues/3937
https://bugzilla.redhat.com/show_bug.cgi?id=1383211
http://www.securityfocus.com/bid/93465
http://www.openwall.com/lists/oss-security/2016/10/08/7
http://lists.opensuse.org/opensuse-updates/2017-01/msg00114.html
http://lists.opensuse.org/opensuse-updates/2017-01/msg00110.html
http://lists.opensuse.org/opensuse-updates/2017-01/msg00103.html
http://lists.opensuse.org/opensuse-updates/2016-12/msg00075.html