CVE-2009-3876 in JRE
Summary
by MITRE
Unspecified vulnerability in Sun Java SE in JDK and JRE 5.0 before Update 22, JDK and JRE 6 before Update 17, SDK and JRE 1.3.x before 1.3.1_27, and SDK and JRE 1.4.x before 1.4.2_24 allows remote attackers to cause a denial of service (memory consumption) via crafted DER encoded data, which is not properly decoded by the ASN.1 DER input stream parser, aka Bug Id 6864911.
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Analysis
by VulDB Data Team • 03/23/2025
The vulnerability identified as CVE-2009-3876 represents a critical denial of service flaw affecting multiple versions of Sun Java SE including JDK and JRE 5.0 through Update 21, JDK and JRE 6 through Update 16, and older SDK and JRE versions 1.3.x through 1.3.1_26 and 1.4.x through 1.4.2_23. This issue specifically targets the ASN.1 DER input stream parser component within the Java runtime environment, creating a scenario where maliciously crafted data can trigger excessive memory consumption. The vulnerability operates through the improper handling of DER encoded data during the decoding process, which constitutes a fundamental flaw in the cryptographic data parsing mechanism. The bug was catalogued under Bug Id 6864911, indicating its classification within Oracle's internal tracking systems for security vulnerabilities.
The technical implementation of this vulnerability stems from the ASN.1 DER input stream parser's inability to properly validate or limit the processing of malformed DER encoded data structures. When the Java runtime encounters specially crafted DER encoded data, the parser enters an inefficient processing loop that consumes increasing amounts of memory without proper bounds checking or resource limits. This memory consumption pattern can escalate rapidly, leading to system resource exhaustion and ultimately causing the Java application or system to become unresponsive or crash entirely. The flaw manifests specifically during the decoding phase of ASN.1 data structures, which are commonly used in cryptographic operations, certificate processing, and secure communication protocols. This weakness directly relates to CWE-400, which categorizes unrestricted resource consumption as a significant security concern, and aligns with ATT&CK technique T1499.004 for resource exhaustion attacks.
The operational impact of this vulnerability extends across numerous enterprise environments where Java applications process external data inputs, particularly those involving certificate validation, secure socket communication, or cryptographic operations. Attackers can exploit this weakness by sending maliciously constructed DER encoded data to any Java application that processes such inputs, potentially affecting web applications, enterprise software, and security infrastructure components. The vulnerability is particularly dangerous because it can be triggered remotely without requiring authentication, making it an attractive target for denial of service attacks. Systems utilizing older Java versions are especially vulnerable, as the patch releases that address this issue were specifically designed to implement proper bounds checking and memory management within the ASN.1 parsing routines. The memory consumption pattern can be particularly devastating in containerized environments or systems with limited memory resources, where a single malicious input can cause complete system failure.
Mitigation strategies for CVE-2009-3876 require immediate deployment of Oracle's security patches and updates, specifically targeting the affected Java versions mentioned in the vulnerability description. Organizations should prioritize updating their Java installations to versions containing the fix for Bug Id 6864911, which implements proper validation and bounds checking for ASN.1 DER input streams. Network segmentation and input validation measures can provide additional protection layers, particularly for legacy systems where immediate patching is not feasible. Security monitoring should include detection of unusual memory consumption patterns in Java applications, as these may indicate exploitation attempts. Implementing proper resource limits and process monitoring can help contain the impact if exploitation occurs. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all Java applications that might be exposed to this attack vector, particularly those handling external certificate or cryptographic data inputs. The remediation process should also include reviewing and updating security policies to ensure proper patch management procedures are in place for Java runtime environments, aligning with industry best practices for maintaining secure software deployments.