CVE-2017-3526 in Java SE
Summary
by MITRE
Vulnerability in the Java SE, Java SE Embedded, JRockit component of Oracle Java SE (subcomponent: JAXP). Supported versions that are affected are Java SE: 6u141, 7u131 and 8u121; Java SE Embedded: 8u121; JRockit: R28.3.13. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, Java SE Embedded, JRockit. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Java SE, Java SE Embedded, JRockit. Note: Applies to client and server deployment of Java. This vulnerability can be exploited through sandboxed Java Web Start applications and sandboxed Java applets. It can also be exploited by supplying data to APIs in the specified Component without using sandboxed Java Web Start applications or sandboxed Java applets, such as through a web service. CVSS 3.0 Base Score 5.9 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 12/20/2020
The vulnerability identified as CVE-2017-3526 represents a critical availability issue within Oracle Java SE and JRockit components, specifically affecting the Java API for XML Processing JAXP subcomponent. This flaw exists in multiple Java versions including Java SE 6u141, 7u131, and 8u121, along with Java SE Embedded 8u121 and JRockit R28.3.13, making it a widespread concern across various deployment environments. The vulnerability's classification as difficult to exploit indicates that while sophisticated attackers can leverage it, the attack vector requires specific conditions that are not trivial to achieve. The security implications extend beyond traditional server deployments to include client-side applications, making it particularly dangerous in environments where users interact with untrusted content.
The technical nature of this vulnerability stems from improper input validation within the JAXP component's XML processing functionality, creating a condition where malformed XML data can trigger unexpected behavior in the Java runtime environment. This flaw manifests as a denial of service condition that can cause complete system hangs or repeated crashes, effectively rendering affected Java applications unusable. The vulnerability's impact is particularly severe because it operates at a foundational level of XML processing, which is extensively used across enterprise applications, web services, and embedded systems. The CVSS 3.0 score of 5.9 reflects the availability impact with a high attack complexity requirement, indicating that while the attack is not trivial, it is achievable through network-based exploitation.
The operational impact of CVE-2017-3526 extends across multiple deployment scenarios, including both client and server environments where Java applications are executed. Attackers can exploit this vulnerability through sandboxed Java Web Start applications and applets, which are commonly used in enterprise environments and web applications where users might encounter untrusted content. Additionally, the vulnerability can be triggered through direct API calls without requiring sandboxed environments, making it exploitable through web services and other application programming interfaces. This broad attack surface significantly increases the potential impact and makes the vulnerability particularly dangerous for organizations running Java-based services. The vulnerability's characteristics align with CWE-129, which addresses improper validation of input boundaries, and can be mapped to ATT&CK technique T1203, representing exploitation of software vulnerabilities for denial of service attacks.
Organizations affected by this vulnerability should prioritize immediate patching of all affected Java versions, as Oracle released security updates specifically addressing this issue. The mitigation strategy should include comprehensive network segmentation to limit exposure, implementing strict firewall rules to restrict access to Java-based services, and monitoring for unusual network traffic patterns that might indicate exploitation attempts. Additionally, organizations should consider disabling unnecessary Java applet and Web Start functionality in browsers and application environments where the vulnerability can be exploited through sandboxed applications. Regular security assessments should be conducted to ensure that all Java installations are properly updated and that no legacy versions remain in production environments. The vulnerability's impact on availability makes it particularly important to maintain redundant systems and implement robust monitoring solutions to detect and respond to exploitation attempts quickly.