Unsafe Deserialization in Oracle Xstream (CVE-2021-39152, CVSS 8.5)

Summary

Vulnerability in Oracle Xstream (CVE-2021-39152). Successful exploitation can lead to full system takeover.

Original description

The description as published by the source.

Impact

The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream with a Java runtime version 14 to 8. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types.

Patches

If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.18.

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-2021-39152.

Credits

m0d9 of the Security Team of Alibaba Cloud 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-2021-39152 has been found in Oracle Xstream.
Successful exploitation can lead to full system takeover. CVSS score: 8.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Oracle Xstream CVE-2021-39152" on the vendor's site.

CVE-2021-39152 (Oracle Xstream) — CWE-502 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
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

Unsafe deserialization (CWE-502) exists in Oracle Xstream.

📍 Affected scope

Check the vendor advisory for the affected versions of Oracle Xstream.

🔥 Severity

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

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Xstream' . 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

1
Identify exposure identify
```
grep -r 'Xstream' . | 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 Xstream を grep し、稼働しているサービス・バージョンを把握する。
2
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"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2021-39152 libxstream-java Fixed in: 1.4.18-1