Unrestricted File Upload in com.thoughtworks.xstream:xstream (CVE-2021-39146, CVSS 8.5)

Summary

Vulnerability in com.thoughtworks.xstream:xstream (CVE-2021-39146). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 1.4.18 or later.

Original description

The description as published by the source.

Impact

The vulnerability may allow a remote attacker to load and execute arbitrary code from a remote host only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types.

Patches

XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

Workarounds

See workarounds for the different versions covering all CVEs.

References

See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for CVE-2021-39146.

Credits

Ceclin and YXXX from the Tencent Security Response Center found and reported the issue to XStream and provided the required information to reproduce it.

For more information

If you have any questions or comments about this advisory:

Open an issue in XStream
Contact us at XStream Google Group

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-2021-39146 has been found in com.thoughtworks.xstream:xstream.
Successful exploitation can lead to full system takeover. CVSS score: 8.5/10.
What to do: upgrade com.thoughtworks.xstream:xstream to 1.4.18 or later.
If unsure, ask your IT team or search "com.thoughtworks.xstream:xstream CVE-2021-39146" on the vendor's site.

CVE-2021-39146 (com.thoughtworks.xstream:xstream) — CWE-434 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
Patched: 1.4.18 — apply immediately
Workaround: See workarounds for the different versions covering all CVEs.
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.

❓ What is the problem

A vulnerability (CWE-434) exists in com.thoughtworks.xstream:xstream.

📍 Affected scope

Check the vendor advisory for the affected versions of com.thoughtworks.xstream:xstream.

🔥 Severity

Severity: High (CVSS 8.5/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 1.4.18.

🛡️ Workaround

Workaround: See workarounds for the different versions covering all CVEs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで com.thoughtworks.xstream:xstream を使っているサービスとバージョンを洗い出す。
2
Apply temporary workaround mitigate
```
See [workarounds](https://x-stream.github.io/security.html#workaround) for the different versions covering all CVEs.
```
パッチが適用されるまでの応急処置として、See workarounds for the different versions covering all CVEs. を実施。回避策の副作用 (機能低下) を確認した上で。
3
Apply patch patch
```
Upgrade com.thoughtworks.xstream:xstream to 1.4.18
```
ステージング環境で 1.4.18 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。
4
Post-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

Maven com.thoughtworks.xstream:xstream

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.18"}]}]