CVE-2021-29505 — XStream is vulnerable to a Remote Command Execution attack
XStream is software for serializing Java objects to XML and back again. A vulnerability in XStream versions prior to 1.4.17 may allow a remote attacker has sufficient rights to execute commands of the host only by manipulating the processed input stream. No user who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types is affected. The vulnerability is patched in version 1.4.17.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Public exploit/PoC (nuclei)+4
- EPSS 77.2% (30-day exploitation probability)+15
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Netapp Snapmanager…).
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (insecure deserialization), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 9.0version 10.0version 11.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 34version 35version 33 | Vulnerable | NIST National Vulnerability Database |
| Netapp | Snapmanager | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Oracle | Banking Cash Management | version 14.5version 14.3version 14.2 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Banking Corporate Lending Process Management | version 14.5.0version 14.3.0version 14.2.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Banking Credit Facilities Process Management | version 14.5.0version 14.3.0version 14.2.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Banking Supply Chain Finance | version 14.2.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Banking Trade Finance Process Management | version 14.5.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Business Activity Monitoring | version 12.2.1.4.0version 12.2.1.3.0version 11.1.1.9.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Communications Brm - Elastic Charging Engine | version 11.3version 12.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Communications Unified Inventory Management | version 7.4.2version 7.4.1version 7.4.0version 7.3.5version 7.3.4 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Enterprise Manager Ops Center | version 12.4.0.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Retail Customer Insights | version 16.0.2version 15.0.2 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Retail Xstore Point Of Service | version 20.0.1version 19.0.2version 18.0.3version 17.0.4version 16.0.6 | Vulnerable | NIST National Vulnerability Database |
| Oracle | WebCenter Portal | version 12.2.1.3.0version 12.2.1.4.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Webcenter Sites | version 12.2.1.4.0version 12.2.1.3.0 | Vulnerable | NIST National Vulnerability Database |
| Xstream | Xstream | < 1.4.17 | Vulnerable | NIST National Vulnerability Database |
| Xstream | Xstream | version < 1.4.17 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | 1.6 | 5.9 | security-advisories@github.com via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 6.5 | CVSS 2.0 | Medium | 8.0 | 6.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 77.23%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor serialized objects in requests and unexpected processes spawned by the runtime.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · x-stream/xstream
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 8.8
- Source status changed · → Modified
- Record created in this database
- 2021
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
20 on the record
- github.com/x-stream/xstream/commit/24fac82191292c6ae25f94508d28b9823f83624f
- www.oracle.com/security-alerts/cpujan2022.html
- www.oracle.com/security-alerts/cpuapr2022.html
- github.com/x-stream/xstream/security/advisories/GHSA-7chv-rrw6-w6fc
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6
- www.oracle.com/security-alerts/cpuoct2021.html
- github.com/x-stream/xstream/commit/f0c4a8d861b68ffc3119cfbbbd632deee624e227
- lists.debian.org/debian-lts-announce/2021/07/msg00004.html
- lists.apache.org/thread.html/r8ee51debf7fd184b6a6b020dc31df25118b0aa612885f12fbe77f04f
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3
- lists.apache.org/thread.html/r8ee51debf7fd184b6a6b020dc31df25118b0aa612885f12fbe77f04f
- security.netapp.com/advisory/ntap-20210708-0007
- www.debian.org/security/2021/dsa-5004
- security.netapp.com/advisory/ntap-20210708-0007/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXI
- www.oracle.com/security-alerts/cpujul2022.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPH
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KV
- x-stream.github.io/CVE-2021-29505.html
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-83050 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
- High CVE-2026-83046 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
- High CVE-2026-83047 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
- High CVE-2026-83048 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
- High CVE-2026-83049 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
- High CVE-2026-83051 Improper Access Control in Oracle WebCenter Portal Sep 15, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-29505 is "XStream is vulnerable to a Remote Command Execution attack", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 77.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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