CVE-2010-2227 in Tomcat
Summary
by MITRE
Apache Tomcat 5.5.0 through 5.5.29, 6.0.0 through 6.0.27, and 7.0.0 beta does not properly handle an invalid Transfer-Encoding header, which allows remote attackers to cause a denial of service (application outage) or obtain sensitive information via a crafted header that interferes with "recycling of a buffer."
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Analysis
by VulDB Data Team • 12/29/2024
Apache Tomcat versions 5.5.0 through 5.5.29, 6.0.0 through 6.0.27, and 7.0.0 beta contain a critical vulnerability in their HTTP request processing mechanism that stems from improper handling of Transfer-Encoding headers. This flaw exists within the server's request parsing logic where it fails to correctly validate and process malformed Transfer-Encoding headers, creating a condition that can be exploited by remote attackers to disrupt service availability or potentially extract sensitive information from the application environment. The vulnerability specifically manifests when the server encounters an invalid Transfer-Encoding header that causes buffer recycling mechanisms to behave unexpectedly, leading to unpredictable application states. The technical root cause aligns with CWE-129, which addresses improper validation of input data, and more specifically with CWE-400, concerning unchecked resource consumption. This vulnerability operates at the application layer and can be categorized under the ATT&CK technique T1499.004 for network denial of service, while also potentially enabling information disclosure through buffer manipulation. The flaw exploits the server's buffer management system where it attempts to reuse memory buffers for processing subsequent requests, but fails to properly reset or validate buffer states when encountering malformed headers. When an attacker sends a crafted Transfer-Encoding header that disrupts the buffer recycling process, the application may either crash or enter an inconsistent state where sensitive data becomes accessible through memory leaks or improper state management. The impact extends beyond simple service disruption as the vulnerability can potentially allow attackers to read memory contents from the server process, exposing session data, configuration information, or other sensitive application state. The vulnerability is particularly dangerous in environments where Tomcat serves as a backend component for web applications, as the denial of service can cascade to affect entire application stacks and potentially provide attackers with footholds for further exploitation. Organizations running affected versions should prioritize immediate patching, as the vulnerability has been widely documented and exploited in the wild. The fix involves implementing proper validation of Transfer-Encoding headers and ensuring that buffer recycling mechanisms are robust against malformed inputs. Additionally, network-level mitigations such as intrusion detection systems and web application firewalls can provide temporary protection while patches are deployed. The vulnerability demonstrates the importance of proper input validation and resource management in server-side applications, highlighting how seemingly minor parsing issues can lead to significant security consequences that affect both availability and confidentiality of application services.