T09 · Insecure Skill Coding Practices
Error
- Location
dream-tools.sh:91- Finding
Unrestricted Arbitrary File Replacement Through --atomic-write
- Content
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" [[ ! -f "$tmpfile" ]] && die "tmp 文件不存在：$tmpfile" # 若目标是 MEMORY.md，检查字符数上限 if [[ "$(realpath "$target" 2>/dev/null)" == "$(realpath "$MEMORY_MD" 2>/dev/null)" ]] || \ [[ "$target" == *"MEMORY.md" ]]; then local size size=$(wc -c < "$tmpfile" | tr -d ' ') if [[ $size -gt $MEMORY_HARD_LIMIT ]]; then die "写入中止：tmp 文件大小 ${size} 字符，超过硬上限 ${MEMORY_HARD_LIMIT}。请先压缩内容。" fi log "MEMORY.md 写入校验通过：${size}/${MEMORY_HARD_LIMIT} 字符" fi ensure_dir "$target" # mv 在同一文件系统上是原子操作 mv "$tmpfile" "$target" log "原子写入完成：$target" } ``` ### Technical Analysis The `--atomic-write` operation accepts caller-controlled source and destination paths without enforcing an allowed directory or destination list. Although special size validation is attempted for paths resembling `MEMORY.md`, every other destination is accepted without scope validation. The function also calls `ensure_dir`, which creates the destination's parent directory, and then uses `mv` to replace the destination. It does not verify that: - The destination is the configured `MEMORY_MD`. - The destination is inside `DREAM_VAULT_PATH` or `OPENCLAW_WORKSPACE`. - The source is an approved temporary file. - The source or destination does not traverse symbolic links. - The destination is a regular file rather than a sensitive configuration or instruction file. The suffix test `[[ "$target" == *"MEMORY.md" ]]` is not a security boundary. It only applies a size limit and still permits an arbitrary path ending in `MEMORY.md`. This behavior contradicts the README claim that file operations ...[truncated 1453 chars]- Remediation
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``` 10. Add tests covering absolute paths, `..` traversal, symlink traversal, paths outside the workspace, and unrelated files ending in `MEMORY.md`. ]]>