Fix shell injection vulnerability in GitHub Actions workflow#18
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Fix shell injection vulnerability in GitHub Actions workflow#18semgrep-code-studentsca023-rgb[bot] wants to merge 1 commit into
semgrep-code-studentsca023-rgb[bot] wants to merge 1 commit into
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Fix a command injection vulnerability in the ShiftLeft workflow by using an environment variable instead of direct interpolation of `github.head_ref`.
## Changes
- Added `BRANCH_NAME` environment variable to safely pass `github.head_ref`
- Replaced direct `${{ github.head_ref }}` interpolation with quoted `"$BRANCH_NAME"` in the run script
## Why
Using `${{ github.head_ref }}` directly in a `run:` step is vulnerable to command injection. An attacker could create a branch with a malicious name (e.g., containing shell metacharacters or commands) that would be executed by the runner. By passing the value through an `env:` block and using double-quoted environment variable expansion, the value is treated as data rather than code, preventing injection attacks.
## Semgrep Finding Details
Using variable interpolation `${{...}}` with `github` context data in a `run:` step could allow an attacker to inject their own code into the runner. This would allow them to steal secrets and code. `github` context data can have arbitrary user input and should be treated as untrusted. Instead, use an intermediate environment variable with `env:` to store the data and use the environment variable in the `run:` script. Be sure to use double-quotes the environment variable, like this: "$ENVVAR".
@267212124 requested Semgrep Assistant generate this pull request to fix [a finding](https://semgrep.dev/orgs/studentsca023_personal_org/findings/722169002) from the detection rule [yaml.github-actions.security.run-shell-injection.run-shell-injection](https://semgrep.dev/r/yaml.github-actions.security.run-shell-injection.run-shell-injection).
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Fix a command injection vulnerability in the ShiftLeft workflow by using an environment variable instead of direct interpolation of
github.head_ref.Changes
BRANCH_NAMEenvironment variable to safely passgithub.head_ref${{ github.head_ref }}interpolation with quoted"$BRANCH_NAME"in the run scriptWhy
Using
${{ github.head_ref }}directly in arun:step is vulnerable to command injection. An attacker could create a branch with a malicious name (e.g., containing shell metacharacters or commands) that would be executed by the runner. By passing the value through anenv:block and using double-quoted environment variable expansion, the value is treated as data rather than code, preventing injection attacks.Semgrep Finding Details
Using variable interpolation
${{...}}withgithubcontext data in arun:step could allow an attacker to inject their own code into the runner. This would allow them to steal secrets and code.githubcontext data can have arbitrary user input and should be treated as untrusted. Instead, use an intermediate environment variable withenv:to store the data and use the environment variable in therun:script. Be sure to use double-quotes the environment variable, like this: "$ENVVAR".@267212124 requested Semgrep Assistant generate this pull request to fix a finding from the detection rule yaml.github-actions.security.run-shell-injection.run-shell-injection.