| Titel | NousResearch hermes-agent 2026.4.16 Path Traversal (CWE-22) |
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| Beschreibung | # Technical Details
A Denial of Service via device path blocklist bypass exists in the `_is_blocked_device()` method in `tools/file_tools.py` of hermes-agent.
The application fails to adequately normalize file paths (missing `os.path.normpath`), only using `os.path.expanduser()` before checking against an exact string match blocklist (`_BLOCKED_DEVICE_PATHS`), allowing bypass using standard UNIX path traversal sequences (e.g., `/dev/./zero`).
# Vulnerable Code
File: tools/file_tools.py
Method: _is_blocked_device()
Why: The function normalizes the input path using only `os.path.expanduser(filepath)` without resolving traversal components (`.` or `..`). The hardcoded blocklist uses exact membership matching, meaning an input like `/dev/./zero` does not match `/dev/zero`, but the OS kernel transparently resolves it, leading to blocked device access.
# Reproduction
1. Deploy `hermes-agent` with the default file toolset enabled.
2. Send a prompt to the agent: `Please use the read_file tool to read the file at path '/dev/./zero'`.
3. The `os.path.expanduser()` will bypass the blocklist, the device file is opened, and the read_file tool will initiate an infinite read.
4. The agent process hangs indefinitely.
# Impact
- Denial of Service (DoS) resulting in the agent session freezing permanently.
- In gateway modes, repeated attempts can exhaust thread pools, causing complete service denial for all users. |
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| Quelle | ⚠️ https://gist.github.com/YLChen-007/1d1aeff404cb88e06ec2fb3377f49fef |
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| Benutzer | Eric-h (UID 97582) |
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| Einreichung | 24.04.2026 14:35 (vor 1 Monat) |
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| Moderieren | 23.05.2026 11:19 (29 days later) |
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| Status | Akzeptiert |
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| VulDB Eintrag | 365314 [NousResearch hermes-agent bis 2026.4.16 read_file Tool tools/file_tools.py _is_blocked_device Directory Traversal] |
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| Punkte | 20 |
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