CVE-2023-22742
git2 does not verify SSH keys by default
Description
libgit2 is a cross-platform, linkable library implementation of Git. When using an SSH remote with the optional 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. Users are encouraged to upgrade to v1.4.5 or v1.5.1. Users unable to upgrade should ensure that all relevant certificates are manually checked.
How to fix CVE-2023-22742
To remediate CVE-2023-22742, upgrade the affected package to a fixed version below.
- —upgrade to 0.16.1 or later
- —upgrade to 0.14.2 or later
- —upgrade to 0.13.5 or later
- —upgrade to 1.1.0+dfsg.1-4+deb11u1 or later
Is CVE-2023-22742 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 0.16.1
- >= 0.14.0, < 0.14.2
- >= 0.0.0-0, < 0.13.5, >= 0.14.0, < 0.14.2
- from 0, < 1.1.0+dfsg.1-4+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |