`decompress`: tar-family extractors write archive entries without a path-traversal check (tar-slip)

Overview

The tar-family extractors in decompress (.tar, .tar.gz, .tar.xz, .tar.bz2, .tar.zst) build each output path from the raw archive entry path and write to it with no traversal check, so a malicious archive can write files outside the destination directory, a "tar-slip" / zip-slip path traversal (CWE-22 / CWE-23).

In src/decompressors/tar_common.rs (tar_extract):

let filepath = entry.path()?;                                    // raw entry path
let filepath = filepath.components().skip(opts.strip).collect::<PathBuf>();
                                     // strips leading components only — keeps `..`
let outpath = to.join(filepath);
// ...
let mut outfile = fs::File::create(&outpath)?;                   // writes anywhere

.components().skip(opts.strip) removes a fixed number of leading path components but leaves interior .. components intact so an entry named e.g. ../../../../home/<user>/.bashrc, or an absolute path, resolves outside to. This affects all platforms.

Affected packages

• decompress >= 0.0.0-0

Remediation

Refer to the advisory for the patched release.