CVE-2014-0075 in Communications Policy Management
Summary
by MITRE
Integer overflow in the parseChunkHeader function in java/org/apache/coyote/http11/filters/ChunkedInputFilter.java in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4 allows remote attackers to cause a denial of service (resource consumption) via a malformed chunk size in chunked transfer coding of a request during the streaming of data.
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Analysis
by VulDB Data Team • 09/27/2022
The vulnerability identified as CVE-2014-0075 represents a critical integer overflow flaw within Apache Tomcat's HTTP 1.1 implementation that affects multiple versions of the popular web application server. This issue resides in the parseChunkHeader function located in the ChunkedInputFilter.java file, which is responsible for processing chunked transfer coding in HTTP requests. The vulnerability manifests when Tomcat encounters malformed chunk size values during the streaming of data, creating a scenario where the application's resource management becomes compromised and potentially exploitable by remote attackers. The integer overflow occurs during the parsing of chunked request headers, specifically when the system attempts to process chunk size values that exceed the maximum representable integer values, leading to unexpected behavior in the application's memory allocation and processing mechanisms.
The technical exploitation of this vulnerability leverages the fundamental flaw in how Tomcat handles chunked transfer encoding, a standard HTTP feature that allows data to be sent in chunks rather than as a single contiguous block. When an attacker crafts a malicious HTTP request with an oversized chunk size value, the integer overflow causes the system to miscalculate the amount of memory required for processing the chunked data. This miscalculation results in the application consuming excessive resources or potentially entering an unstable state where it fails to properly handle subsequent requests. The vulnerability is particularly dangerous because it operates at the HTTP protocol level and can be triggered through normal web traffic without requiring any special privileges or authentication. According to CWE-190, this represents an integer overflow vulnerability that can lead to resource exhaustion, which aligns with the denial of service characteristics observed in this exploit.
The operational impact of CVE-2014-0075 extends beyond simple service disruption to encompass broader system stability and resource management concerns that can affect entire web applications hosted on vulnerable Tomcat instances. When exploited, this vulnerability can cause the target server to consume excessive memory and CPU resources, leading to performance degradation or complete service unavailability for legitimate users. The resource consumption aspect of this vulnerability makes it particularly dangerous in high-traffic environments where multiple concurrent requests could trigger cascading failures. Attackers can leverage this weakness to perform sustained denial of service attacks that exhaust system resources without necessarily requiring sophisticated techniques or deep system knowledge. The vulnerability affects Apache Tomcat versions prior to 6.0.40, 7.0.53, and 8.0.4, indicating that a significant portion of the web application server market was potentially exposed to this risk.
Mitigation strategies for CVE-2014-0075 focus primarily on immediate version upgrades to patched releases that address the integer overflow in the chunked input filtering mechanism. Organizations should prioritize upgrading their Tomcat installations to versions 6.0.40, 7.0.53, or 8.0.4 and higher, depending on their current deployment. The patched versions implement proper bounds checking and overflow protection mechanisms that prevent the malicious chunk size values from causing resource exhaustion. Network-level protections such as web application firewalls and rate limiting can provide additional defense-in-depth measures while awaiting patch deployment. System administrators should also implement monitoring and alerting for unusual resource consumption patterns that might indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service, and the mitigation strategies align with defensive practices outlined in the privilege escalation and resource exhaustion categories. Organizations should conduct thorough vulnerability assessments to identify all affected systems and establish patch management processes to prevent similar issues in the future. The vulnerability also highlights the importance of proper input validation and the need for robust error handling in protocol parsing components that process untrusted network data.