Path Traversal in ftp-srv (CVE-2020-26299)
Summary
Path traversal in ftp-srv (CVE-2020-26299). Risk of unauthorized operations or information disclosure. Exploitable via CWD. Mitigation: upgrade to 4.4.0 or later.
Original description
The description as published by the source.
Impact
Clients of FTP servers utilizing ftp-srv hosted on Windows machines can escape the FTP user's defined root folder using the expected FTP commands, for example, CWD and UPDR.
Background
When windows separators exist within the path (\), path.resolve leaves the upper pointers intact and allows the user to move beyond the root folder defined for that user. We did not take that into account when creating the path resolve function.
Patches
None at the moment.
Workarounds
There are no workarounds for windows servers. Hosting the server on a different OS mitigates the issue.
References
Issues:
https://github.com/autovance/ftp-srv/issues/167
https://github.com/autovance/ftp-srv/issues/225
For more information
If you have any questions or comments about this advisory:
Open an issue at https://github.com/autovance/ftp-srv.
Please email us directly; security@autovance.com.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-26299 has been found in ftp-srv.
Attackers can target a specific entry point like CWD over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade ftp-srv to 4.4.0 or later.
If unsure, ask your IT team or search "ftp-srv CVE-2020-26299" on the vendor's site.
CVE-2020-26299 (ftp-srv) — CWE-22
Attack surface: CWD / UPDR / path.resolve
Patched: 4.4.0 — apply immediately
Workaround: There are no workarounds for windows servers.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in ftp-srv. Attackers reach the vulnerable code path via CWD.
Check the vendor advisory for the affected versions of ftp-srv. Attack surface: CWD / UPDR / path.resolve.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 4.4.0.
Workaround: There are no workarounds for windows servers.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'ftp-srv' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'ftp-srv' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
ftp-srvを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
There are no workarounds for windows servers.パッチが適用されるまでの応急処置として、There are no workarounds for windows servers. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade ftp-srv to 4.4.0ステージング環境で 4.4.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web npmjs.com