Vulnerability Database

391,289

Total vulnerabilities in the database

CVE-2009-3866 — sun / jdk

Permissions, Privileges, and Access Controls

The Java Web Start Installer in Sun Java SE in JDK and JRE 6 before Update 17 does not properly use security model permissions when removing installer extensions, which allows remote attackers to execute arbitrary code by modifying a certain JNLP file to have a URL field that points to an unintended trusted application, aka Bug Id 6872824.

  • Published: Nov 5, 2009
  • Updated: Sep 29, 2026
  • CVE: CVE-2009-3866
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v2:

  • Severity: High
  • Score: 9.3
  • AV:N/AC:M/Au:N/C:C/I:C/A:C

CWEs:

Software Affected versions
sun / jdk = 1.6.0-update_1
sun / jdk = 1.6.0-update_10
sun / jdk = 1.6.0-update_11
sun / jdk = 1.6.0-update_12
sun / jdk = 1.6.0-update_13
sun / jdk = 1.6.0-update_14
sun / jdk = 1.6.0-update_15
sun / jdk = 1.6.0-update_16
sun / jdk = 1.6.0-update_3
sun / jdk = 1.6.0-update_4
sun / jdk = 1.6.0-update_5
sun / jdk = 1.6.0-update_6
sun / jdk = 1.6.0-update_7
sun / jdk = 1.6.0-update_8
sun / jdk = 1.6.0-update_9
sun / jre = 1.6.0-update_1
sun / jre = 1.6.0-update_10
sun / jre = 1.6.0-update_11
sun / jre = 1.6.0-update_12
sun / jre = 1.6.0-update_13
sun / jre = 1.6.0-update_14
sun / jre = 1.6.0-update_15
sun / jre = 1.6.0-update_16
sun / jre = 1.6.0-update_2
sun / jre = 1.6.0-update_3
sun / jre = 1.6.0-update_4
sun / jre = 1.6.0-update_5
sun / jre = 1.6.0-update_6
sun / jre = 1.6.0-update_7
sun / jre = 1.6.0-update_8
sun / jre = 1.6.0-update_9

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.