Arbitrary Command Injection Affecting gh package, versions *


Severity

Recommended
0.0
critical
0
10

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  • Snyk ID SNYK-DEBIAN13-GH-8383879
  • published 19 Nov 2024
  • disclosed 14 Nov 2024

How to fix?

There is no fixed version for Debian:13 gh.

NVD Description

Note: Versions mentioned in the description apply only to the upstream gh package and not the gh package as distributed by Debian. See How to fix? for Debian:13 relevant fixed versions and status.

The GitHub CLI version 2.6.1 and earlier are vulnerable to remote code execution through a malicious codespace SSH server when using gh codespace ssh or gh codespace logs commands. This has been patched in the cli v2.62.0.

Developers connect to remote codespaces through an SSH server running within the devcontainer, which is generally provided through the [default devcontainer image]( https://docs.github.com/en/codespaces/setting-up-your-project-for-codespaces/adding-a-dev-container-... https://docs.github.com/en/codespaces/setting-up-your-project-for-codespaces/adding-a-dev-container-configuration/introduction-to-dev-containers#using-the-default-dev-container-configuration) . GitHub CLI [retrieves SSH connection details]( https://github.com/cli/cli/blob/30066b0042d0c5928d959e288144300cb28196c9/internal/codespaces/rpc/inv... https://github.com/cli/cli/blob/30066b0042d0c5928d959e288144300cb28196c9/internal/codespaces/rpc/invoker.go#L230-L244 ), such as remote username, which is used in [executing ssh commands]( https://github.com/cli/cli/blob/e356c69a6f0125cfaac782c35acf77314f18908d/pkg/cmd/codespace/ssh.go#L2... https://github.com/cli/cli/blob/e356c69a6f0125cfaac782c35acf77314f18908d/pkg/cmd/codespace/ssh.go#L263 ) for gh codespace ssh or gh codespace logs commands.

This exploit occurs when a malicious third-party devcontainer contains a modified SSH server that injects ssh arguments within the SSH connection details. gh codespace ssh and gh codespace logs commands could execute arbitrary code on the user's workstation if the remote username contains something like -oProxyCommand="echo hacked" #. The -oProxyCommand flag causes ssh to execute the provided command while # shell comment causes any other ssh arguments to be ignored.

In 2.62.0, the remote username information is being validated before being used.

CVSS Scores

version 3.1
Expand this section

NVD

Recommended
9.6 critical
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    Required
  • Scope (S)
    Changed
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    High