Git credentials are exposed in Atlantis logs

Summary

Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server.

Atlantis logs contains GitHub credentials (tokens ghs_...) when they are rotated. This enables an attacker able to read these logs to impersonate Atlantis application and to perform actions on GitHub.

When Atlantis is used to administer a GitHub organization, this enables getting administration privileges on the organization.

This was reported in https://github.com/runatlantis/atlantis/issues/4060 and fixed in https://github.com/runatlantis/atlantis/pull/4667 . The fix was included in Atlantis v0.30.0.

Details

Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer.

While auditing the Kubernetes/Argo CD/Atlantis deployment of some company, the following set-up was encountered:

• Most employees have read-only access to Argo CD, enabling them to see the health of deployed applications.
• Atlantis was deployed as an Argo CD application.
• Atlantis was used to manage the configuration of a GitHub organization (such as team members), using Terraform's GitHub integration.

Atlantis logs on Argo CD contained lines such as:

{"level":"debug","ts":"2024-11-07T17:58:30.636Z","caller":"vcs/gh_app_creds_rotator.go:58","msg":"Refreshing git tokens for Github App","json":{}}
{"level":"debug","ts":"2024-11-07T17:58:30.637Z","caller":"vcs/gh_app_creds_rotator.go:64","msg":"token ghs_[REDACTED]","json":{}}
{"level":"debug","ts":"2024-11-07T17:58:30.637Z","caller":"vcs/git_cred_writer.go:36","msg":"git credentials file has expected contents, not modifying","json":{}}

This enabled employees with read-only access to Argo CD to get administration privileges on the GitHub organization, compromising all repositories. As some repositories were used for Infrastructure-as-Code deployment (with Atlantis), this enabled the security auditors to get cluster admin privileges on most Kubernetes clusters.

While the set-up "most employees have read-only access to Argo CD" can be seen as dangerous, this should not incur such security risk (cf. https://argo-cd.readthedocs.io/en/stable/operator-manual/security/). The main issue here was that the logs contained privileged GitHub tokens as they were obtained by Atlantis.

This issue was already reported (https://github.com/runatlantis/atlantis/issues/4060) and fixed (https://github.com/runatlantis/atlantis/pull/4667) but no security advisory was published on https://github.com/runatlantis/atlantis/security and no CVE was assigned (https://app.opencve.io/cve/?&vendor=runatlantis&product=atlantis only lists CVE-2022-24912, which is unrelated).

Could you please publish a security advisory?

PoC

Complete instructions, including specific configuration details, to reproduce the vulnerability.

cf. https://github.com/runatlantis/atlantis/issues/4060 for more details.

Impact

What kind of vulnerability is it? Who is impacted?

• This leaks sensitive GitHub tokens in the log files (CWE-532: Insertion of Sensitive Information into Log File).
• This could enable anyone with log read access to compromiseGitHub organizations managed by Atlantis.
• This impact at least users using Atlantis with Github application and integration.