CVE-2009-3877 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 HTTP headers, which are not properly parsed by the ASN.1 DER input stream parser, aka Bug Id 6864911.
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Analysis
by VulDB Data Team • 08/27/2021
This vulnerability resides within the Sun Java SE runtime environment affecting multiple versions of Java Development Kit and Java Runtime Environment across different major releases. The flaw manifests in the ASN.1 DER input stream parser component which is responsible for processing encoded data structures used in various network protocols and security applications. The vulnerability specifically impacts the parsing logic when handling crafted HTTP headers that contain malformed ASN.1 encoded data. This issue represents a classic denial of service condition where maliciously constructed input can cause excessive memory consumption within the Java virtual machine. The vulnerability has been categorized under CWE-129 as an insufficient input validation problem, where the parser fails to properly validate the structure and length of incoming ASN.1 encoded data streams. The attack vector operates through remote network connections where an attacker can send specially crafted HTTP requests containing malformed ASN.1 data within HTTP headers that trigger the vulnerable parsing logic. This vulnerability aligns with ATT&CK technique T1499.001 which involves network denial of service attacks targeting application-level protocols.
The technical implementation of this vulnerability exploits the lack of proper bounds checking within the ASN.1 DER parser when processing input streams. When the parser encounters malformed ASN.1 encoded data within HTTP headers, it fails to properly validate the structure of the encoded data, leading to unbounded memory allocation patterns. The parser continues to allocate memory resources without proper bounds enforcement, eventually consuming all available memory on the target system. This memory consumption occurs during the parsing phase of HTTP header processing rather than during normal application execution, making it particularly difficult to detect and mitigate. The vulnerability affects multiple Java versions simultaneously due to the shared ASN.1 parsing component across different releases, demonstrating how core library components can create widespread impact. The issue is particularly concerning because it operates at the protocol parsing layer, meaning that any application using HTTP headers with ASN.1 encoded content could be affected regardless of the application's specific functionality or security controls.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise system stability and availability. When exploited successfully, the vulnerability can cause complete system resource exhaustion leading to application crashes or system hangs. The memory consumption pattern is typically gradual but persistent, allowing attackers to maintain the denial of service condition for extended periods. This makes the vulnerability particularly dangerous in production environments where system uptime and reliability are critical. Organizations running Java-based web applications, enterprise servers, or any system that processes HTTP headers are at risk. The vulnerability can be exploited through various network protocols including HTTP, HTTPS, and other services that utilize HTTP header parsing. Attackers can leverage this vulnerability to perform resource exhaustion attacks against web servers, application servers, or any Java-based service that processes HTTP requests containing maliciously crafted headers. The low complexity of exploitation and high impact make this vulnerability particularly attractive to threat actors seeking to disrupt services.
Mitigation strategies for this vulnerability primarily focus on immediate patch application as provided by Oracle through their security updates. Organizations should prioritize updating all affected Java installations to versions that contain the patched ASN.1 parser implementation. Network-level protections such as web application firewalls and intrusion prevention systems can provide temporary defense by filtering out malformed HTTP headers before they reach the Java application. Implementing rate limiting and connection throttling mechanisms can help reduce the effectiveness of sustained denial of service attacks. Additionally, configuring Java applications to use stricter security policies and input validation can provide defense in depth. The vulnerability demonstrates the importance of proper input validation and bounds checking in security-critical components, aligning with security best practices outlined in the OWASP Top Ten and other industry standards. System administrators should also monitor for unusual memory consumption patterns and implement automated alerting for resource exhaustion conditions. Regular security assessments and vulnerability scanning should include checks for outdated Java installations to prevent exploitation of this and similar vulnerabilities.