| Package | Affected versions | Patched versions |
|---|---|---|
| github.com/theupdateframework/go-tuf/v2 | < 2.4.1 | 2.4.1 |
| go-tuf | ≥ 2.0.0, < 2.4.1 | 2.4.1 |
go-tuf's TAP 4 Multirepo Client uses the map file repository name string (repoName) as a filesystem path component when selecting the local metadata cache directory. If an application accepts a map file from an untrusted source, an attacker can supply a repoName containing traversal (e.g., ../escaped-repo) and cause go-tuf to create directories and write the root metadata file outside the intended LocalMetadataDir cache base, within the running process's filesystem permissions.
| Field | Value |
|---|---|
| File | metadata/multirepo/multirepo.go |
| Function | (*MultiRepoClient) initTUFClients() error |
| Callsite | metadataDir := filepath.Join(client.Config.LocalMetadataDir, repoName) (around line 129 at the pinned commit) |
When the TAP 4 map file content is attacker-controlled, this enables arbitrary file write relative to the process permissions (via metadata persistence during client initialization). This can be used to overwrite files writable by the process (for example, configuration files in writable directories) and may enable further compromise depending on the deployment environment.
Note: Exploitability is deployment-dependent. If the map file is always local and trusted (not attacker-controlled), this reduces to a misconfiguration risk rather than a remotely triggerable issue.
repositories keys are attacker-controlled (for example: fetched from a URL, supply-chain substituted, or otherwise attacker-influenced input).DisableLocalCache=false) and the configured LocalMetadataDir is writable by the running process.Claim Ceiling: HIGH when the map file is attacker-controlled; if the map file is always local and trusted, this is closer to a configuration footgun and likely lands as MEDIUM/LOW.
| Field | Value |
|---|---|
| Affected Versions |
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site free| ≤ 2.4.0 |
| Verified On | Commit bde5f18dc95dfac365fc452ee4e278e5fd66d4b4 (tag v2.4.0) |
Note: First affected version has not been bisected.
Attachments include poc.zip with:
canonical.log (contains [CALLSITE_HIT], [PROOF_MARKER])control.log (contains [CALLSITE_HIT], [NC_MARKER], does not contain [PROOF_MARKER])fix.patch (minimal validation sketch)Expected: Multirepo repository names are treated as identifiers; a TAP 4 map file containing traversal or absolute paths is rejected (or safely normalized so that all writes stay under LocalMetadataDir).
Actual: A traversal repoName escapes LocalMetadataDir and go-tuf persists root.json under the escaped path during initialization.
rm -rf _poc
mkdir -p _poc
unzip -q -o poc.zip -d _poc
cd _poc/poc
make canonical
make control
. / ..).DisableLocalCache=true).Validate multirepo repository names as identifiers (not paths) before using them in filepath.Join. Reject:
/ and \). and ..)If it is important to accept a wider set of repo names, a safer alternative is to map repo names to a stable, validated directory name (for example via encoding or hashing) and to ensure all writes stay under the cache base directory.
Reported by: Oleh