1 Vulnerability Overview
Recently, the Git project disclosed CVE-2018-17456, a vulnerability in Git that can cause arbitrary code execution when a user clones a malicious repository. An attacker can take control of a target host by exploiting this vulnerability and at the same time using social engineering methods such as phishing. Git encourages all users to update their clients to protect themselves.
Similar to CVE-2017-1000117, this vulnerability can cause option injection attacks related to submodules. It allows the URL field in the .gitModule file to start with a dash (-). As a result, when performing the “git clone” operation, the process interprets this URL as an option, thus leading to arbitrary code execution.
2 Scope of Impact
- Git 2.14.*< 2.14.5
- Git 2.15.*< 2.15.3
- Git 2.16.*< 2.16.5
- Git 2.17.*< 2.17.2
- Git 2.18.*< 2.18.1
- Git 2.19.1
- Git 2.18.1
- Git 2.17.2
- Git 2.16.5
- Git 2.15.3
- Git 2.14.5
Software embedded with Git is also affected by this vulnerability, as shown in the following table.
|Affected Version||Unaffected Version|
|GitHub Desktop||GitHub Desktop <=1.4.1||GitHub Desktop 1.4.2
GitHub Desktop 1.4.3-beta0
3 Check for the Vulnerability
Users can run the following command to check the version of Git in use and determine whether the version is affected by the vulnerability by reference to chapter 2 Scope of Impact.
4 Vulnerability Protection
The Git project has released new versions to patch the vulnerability in question. Affected users should download these updates as soon as possible to protect themselves. Before the upgrade, users should avoid cloning untrusted repositories to protect their systems.
Following are links to the updates for different operating systems:
- Mac OS X:
For example, for a Windows environment, users can directly download the latest version from the first link listed above and then install it, which will overwrite the earlier version. Alternatively, they can run the following command to upgrade Git for Windows:
GitHub Desktop and Atom contain an earlier version of GitLab and so are also affected by this vulnerability, for which the Git project has also released a corresponding update. Affected users are advised to upgrade their software as soon as possible.
|Affected Software||Download Link|
|GitHub Desktop||Windows: https://central.github.com/deployments/desktop/desktop/latest/win32?format=msi|
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