Security Vulnerability CVE-2021-39144 - Complete Analysis and Details
Red Hot Cyber
Cybersecurity is about sharing. Recognize the risk, combat it, share your experiences, and encourage others to do better than you.
Search
Enterprise BusinessLog 320x200 1
2nd Edition GlitchZone RHC 970x120 2

CVE-2021-39144

View the latest critical CVEs issued
This is a free service offered by Red Hot Cyber to the community. It allows you to view, on a single page, information about a single CVE from the National Vulnerability Database (NVD) and the National Institute of Standards and Technology (NIST) of the United States of America, the Forum of Incident Response and Security Teams (FIRST) regarding the EPSS score and percentile, data from the KEV catalog of the Cybersecurity and Infrastructure Security Agency (CISA), as well as selected resources from Red Hot Cyber and other international sources.

National Vulnerability Database Information

Description: XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker has sufficient rights to execute commands of the 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. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

CVSS Base Score: 8.5 (v3.1)

The **CVSS Base Score** is a score from **0 to 10** that represents the intrinsic severity of a vulnerability. A higher score indicates greater severity.

Value
0.02.55.07.510.0
Published on: 08/23/2021 18:15:12
Last modified: 10/24/2025 14:47:35
NIST: CVE source from the National Vulnerability Database (NVD)

CVSS Metrics Details

  • Base Severity: HIGH
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
  • Attack Vector: NETWORK
  • Attack Complexity: HIGH
  • Privileges Required: LOW
  • User Interaction: NONE
  • Scope: CHANGED
  • Confidentiality Impact: HIGH
  • Integrity Impact: HIGH
  • Availability Impact: HIGH

Common Weakness Enumeration (CWE)

Database CWE: v4.18

CWE-94: Improper Control of Generation of Code ('Code Injection') ↗

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

CWE-502: Deserialization of Untrusted Data ↗

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

CWE-306: Missing Authentication for Critical Function ↗

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Fonte: MITRE CWE


FIRST Information

EPSS Score: 0.9438

The **EPSS (Exploit Prediction Scoring System)** is a score from **0 to 1** that indicates the **probability** that a vulnerability will be exploited in the real world in the next 30 days. A higher value indicates a greater likelihood of exploitation.

Value
0.00.250.50.751.0

Percentile: 0.9997

The **Percentile** indicates how much higher this vulnerability's EPSS score is compared to all other vulnerabilities in the EPSS database. For example, a percentile of 0.90 (90%) means that 90% of vulnerabilities have an EPSS score equal to or lower than the current one.

Value
0.00.250.50.751.0

*Data updated as of: 2025-12-13


CISA Information (Known Exploited Vulnerabilities)

The **CISA KEV Catalog** lists vulnerabilities that have been **actively exploited in the real world**. If a CVE is present in this catalog, it indicates that the threat is immediate and mitigation should be a top priority.

CVE **CVE-2021-39144** **IS PRESENT** in the CISA KEV Catalog!

  • Vulnerability Name: XStream Remote Code Execution Vulnerability
  • Short Description: XStream contains a remote code execution vulnerability that allows an attacker to manipulate the processed input stream and replace or inject objects that result in the execution of a local command on the server. This vulnerability can affect multiple products, including but not limited to VMware Cloud Foundation.
  • Date Added to KEV: 03/10/2023
  • Vendor/Product: XStream / XStream
  • Required Action: Apply updates per vendor instructions.
  • Due Date: 03/31/2023

Articles published on Red Hot Cyber


NVD References

Exploit PoC from GitHub