See https://github.com/libgit2/libgit2/security/advisories/GHSA-8643-3wh5-rmjq. """ libgit2, when compiled using the optional, included libssh2 backend, fails to verify SSH keys by default. Description When using an SSH remote with the optional, included libssh2 backend, libgit2 does not perform certificate checking by default. Prior versions of libgit2 require the caller to set the certificate_check field of libgit2's git_remote_callbacks structure - if a certificate check callback is not set, libgit2 does not perform any certificate checking. This means that by default - without configuring a certificate check callback, clients will not perform validation on the server SSH keys and may be subject to a man-in-the-middle attack. Beginning in libgit2 v1.4.5 and v1.5.1, libgit2 will now perform host key checking by default. Users can still override the default behavior using the certificate_check function. The libgit2 security team would like to thank the Julia and Rust security teams for responsibly disclosing this vulnerability and assisting with fixing the vulnerability. Users are encouraged to upgrade to v1.4.5 or v1.5.1. """
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/data/glsa.git/commit/?id=781f9b3a3d3c32e196db69205e615bdfd40b6c49 commit 781f9b3a3d3c32e196db69205e615bdfd40b6c49 Author: GLSAMaker <glsamaker@gentoo.org> AuthorDate: 2024-11-06 14:15:55 +0000 Commit: Hans de Graaff <graaff@gentoo.org> CommitDate: 2024-11-06 14:16:06 +0000 [ GLSA 202411-05 ] libgit2: Multiple Vulnerabilities Bug: https://bugs.gentoo.org/891525 Bug: https://bugs.gentoo.org/923971 Signed-off-by: GLSAMaker <glsamaker@gentoo.org> Signed-off-by: Hans de Graaff <graaff@gentoo.org> glsa-202411-05.xml | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+)