CVE-2021-39159: Remote code execution in Binderhub

First published: Wed Aug 25 2021(Updated: )

### Impact A remote code execution vulnerability has been identified in BinderHub, where providing BinderHub with maliciously crafted input could execute code in the BinderHub context, with the potential to egress credentials of the BinderHub deployment, including JupyterHub API tokens, kubernetes service accounts, and docker registry credentials. This may provide the ability to manipulate images and other user created pods in the deployment, with the potential to escalate to the host depending on the underlying kubernetes configuration. ### Patches Patch below, or [on GitHub](https://github.com/jupyterhub/binderhub/commit/195caac172690456dcdc8cc7a6ca50e05abf8182.patch) ```diff From 9f4043d9dddc1174920e687773f27b7933f48ab6 Mon Sep 17 00:00:00 2001 From: Riccardo Castellotti <rcastell@cern.ch> Date: Thu, 19 Aug 2021 15:49:43 +0200 Subject: [PATCH] Explicitly separate git-ls-remote options from positional arguments --- binderhub/repoproviders.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/binderhub/repoproviders.py b/binderhub/repoproviders.py index f33347b..5d4b87c 100755 --- a/binderhub/repoproviders.py +++ b/binderhub/repoproviders.py @@ -484,7 +484,7 @@ class GitRepoProvider(RepoProvider): self.sha1_validate(self.unresolved_ref) except ValueError: # The ref is a head/tag and we resolve it using `git ls-remote` - command = ["git", "ls-remote", self.repo, self.unresolved_ref] + command = ["git", "ls-remote", "--", self.repo, self.unresolved_ref] result = subprocess.run(command, universal_newlines=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) if result.returncode: raise RuntimeError("Unable to run git ls-remote to get the `resolved_ref`: {}".format(result.stderr)) -- 2.25.1 ``` ### Workarounds Disable the git repo provider by specifying the `BinderHub.repo_providers` config, e.g.: ```python from binderhub.repoproviders import (GitHubRepoProvider, GitLabRepoProvider, GistRepoProvider, ZenodoProvider, FigshareProvider, HydroshareProvider, DataverseProvider) c.BinderHub.repo_providers = { 'gh': GitHubRepoProvider, 'gist': GistRepoProvider, 'gl': GitLabRepoProvider, 'zenodo': ZenodoProvider, 'figshare': FigshareProvider, 'hydroshare': HydroshareProvider, 'dataverse': DataverseProvider, } ``` ### References Credit: Jose Carlos Luna Duran (CERN) and Riccardo Castellotti (CERN). ### For more information If you have any questions or comments about this advisory: * Email us at [security@ipython.org](mailto:security@ipython.org)

Credit: security-advisories@github.com security-advisories@github.com

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• collector/nvd-index
• agent/type
• agent/weakness
• agent/author
• agent/remedy
• agent/softwarecombine
• collector/mitre-cve
• source/MITRE
• agent/title
• agent/severity
• agent/description
• agent/first-publish-date
• agent/event
• collector/github-advisory-latest
• source/GitHub
• alias/GHSA-9jjr-qqfp-ppwx
• alias/CVE-2021-39159
• agent/software-canonical-lookup
• agent/references
• agent/last-modified-date
• collector/nvd-cve
• source/NVD
• collector/github-advisory
• agent/trending
• agent/tags
• agent/source
• vendor/jupyter
• canonical/jupyter binderhub
• package-manager/pip