PYSEC-2026-2506
GuardDog: Unsanitized human-readable scan output allows terminal escape injection from malicious package content
Details
# Summary GuardDog includes attacker-controlled filenames, file locations, messages, and code snippets in its default human-readable output without escaping terminal control characters. A malicious package can therefore inject ANSI or OSC escape sequences into analyst terminals or CI logs.
# Description The finding formatter stores file paths and snippets from scanned content:
```python location = file_path + ":" + str(start_line) finding = { "location": location, "code": code, "message": result["extra"]["message"], } ```
The human-readable reporter later prints these values directly:
```python " * " + finding["message"] + " at " + finding["location"] + "\n " + _format_code_line_for_output(finding["code"]) ```
No escaping is applied for control characters such as `\x1b`. A malicious package can therefore ship a filename like:
```text evil\x1b[2J.py ```
or matched source lines containing terminal escapes, which survive into the final CLI output.
# Reproduction summary 1. Create a file whose name contains `\x1b[2J`. 2. Feed a semgrep-style result referencing that file into `Analyzer._format_semgrep_response()`. 3. Render the result with `HumanReadableReporter.print_scan_results()`. 4. The output string contains the raw escape bytes, which a terminal may interpret.
# Key code paths - `guarddog/analyzer/analyzer.py:377-392` - `guarddog/reporters/human_readable.py:36-42` - `guarddog/reporters/human_readable.py:84-91`
# Practical impact This can be used to: - clear or rewrite analyst terminal output - inject misleading or spoofed log content in CI - emit clickable OSC 8 hyperlinks or title changes in compatible terminals
# Prior public disclosure check As of 2026-03-18, no matching public GitHub advisory, CVE, or public repo issue was found for this specific bug.
# Suggested fix Escape or strip terminal control characters before rendering any attacker-controlled value in human-readable output. This should cover package names, file paths, messages, and code snippets.
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Affected packages
2.6.0No fixed version published yet for guarddog (pip). Pin to a known-safe version or switch to an alternative.