CVE-2007-3698 in JRE
Summary
by MITRE
The Java Secure Socket Extension (JSSE) in Sun JDK and JRE 6 Update 1 and earlier, JDK and JRE 5.0 Updates 7 through 11, and SDK and JRE 1.4.2_11 through 1.4.2_14, when using JSSE for SSL/TLS support, allows remote attackers to cause a denial of service (CPU consumption) via certain SSL/TLS handshake requests.
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Analysis
by VulDB Data Team • 07/22/2019
The vulnerability described in CVE-2007-3698 represents a critical denial of service flaw within the Java Secure Socket Extension implementation across multiple versions of Sun's Java Development Kit and Java Runtime Environment. This issue specifically affects SSL/TLS handshake processing where malicious actors can exploit a weakness in the JSSE library to consume excessive CPU resources, effectively rendering systems unavailable to legitimate users. The vulnerability impacts a wide range of Java versions including JDK and JRE 6 Update 1 and earlier, JDK and JRE 5.0 Updates 7 through 11, and SDK and JRE 1.4.2_11 through 1.4.2_14, indicating a long-standing flaw that affected multiple major Java release lines.
The technical root cause of this vulnerability lies in how the JSSE implementation handles certain malformed or specially crafted SSL/TLS handshake requests during the cryptographic negotiation process. When processing these specific handshake messages, the Java runtime enters into an inefficient processing loop that consumes disproportionate CPU cycles without properly validating or rejecting the malformed requests. This behavior creates a resource exhaustion condition where legitimate SSL/TLS connections cannot be established or maintained, as system resources become consumed by the malicious handshake attempts. The flaw operates at the protocol level within the SSL/TLS implementation, specifically during the initial handshake phase when clients and servers negotiate cryptographic parameters and establish secure connections.
From an operational perspective, this vulnerability presents a significant risk to any system running affected Java versions that provide SSL/TLS services to remote clients. Attackers can exploit this weakness by initiating multiple simultaneous SSL/TLS handshake requests that trigger the CPU consumption behavior, leading to system performance degradation or complete service unavailability. The impact extends beyond simple denial of service as the excessive CPU utilization can affect other applications running on the same system, potentially causing cascading failures. Organizations relying on Java-based web servers, application servers, or any SSL/TLS enabled services are particularly vulnerable, as this attack can be executed with minimal resources and can be automated to maximize impact. The vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the denial of service category, specifically targeting system resources through protocol manipulation.
The security implications of CVE-2007-3698 extend beyond immediate service disruption to encompass broader system stability concerns. When exploited, this vulnerability can lead to complete system lockups or require manual intervention to restore normal operations, including system reboots or process restarts. Network administrators must consider the potential for this vulnerability to be used as part of larger attack campaigns, where initial access might be followed by resource exhaustion to prevent system recovery or to mask other malicious activities. The vulnerability also highlights the importance of proper input validation and resource management in cryptographic libraries, as the flaw demonstrates how improper handling of protocol messages can lead to system-wide availability issues. Organizations should implement monitoring solutions to detect unusual CPU usage patterns that might indicate exploitation attempts, while also ensuring prompt patch deployment to address the underlying implementation issues in the JSSE library.
The remediation strategy for this vulnerability requires immediate patching of affected Java installations to the latest available versions that contain fixes for the SSL/TLS handshake processing logic. System administrators should prioritize updating all Java installations across their infrastructure, particularly those serving SSL/TLS traffic, and conduct thorough testing to ensure that patch deployment does not introduce compatibility issues with existing applications. Additionally, network-level mitigations such as rate limiting for SSL/TLS handshake requests and implementing intrusion detection systems that can identify and block suspicious handshake patterns provide additional defense layers. Organizations should also review their Java application configurations to ensure that SSL/TLS implementations are properly tuned and that appropriate resource limits are enforced to prevent exploitation attempts from causing system-wide impact. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date cryptographic libraries and the potential consequences of failing to address known security flaws in widely used software components.