CVE-2003-0057 in Hypermail
Summary
by MITRE
Multiple buffer overflows in Hypermail 2 before 2.1.6 allows remote attackers to cause a denial of service and possibly execute arbitrary code (1) via a long attachment filename that is not properly handled by the hypermail executable, or (2) by connecting to the mail CGI program from an IP address that reverse-resolves to a long hostname.
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Analysis
by VulDB Data Team • 06/28/2021
The vulnerability described in CVE-2003-0057 represents a critical security flaw affecting Hypermail 2 versions prior to 2.1.6, specifically targeting buffer overflow conditions that can be exploited remotely to achieve denial of service and potential arbitrary code execution. This vulnerability exists within the mail archiving and retrieval system that processes email attachments and hostname resolution, creating multiple attack vectors that demonstrate the complexity of buffer management in web-based email applications. The flaw manifests in two distinct scenarios where improper input validation allows attackers to manipulate memory structures through crafted inputs that exceed allocated buffer boundaries.
The technical implementation of this vulnerability involves two primary attack vectors that exploit different aspects of the Hypermail application's input handling mechanisms. The first vector occurs when processing email attachments with excessively long filename strings that are not properly sanitized before being processed by the hypermail executable, leading to memory corruption through buffer overflows. The second vector exploits hostname resolution behavior where connections made from IP addresses that reverse-resolve to unusually long hostnames trigger similar buffer overflow conditions within the mail CGI program. Both scenarios demonstrate poor input validation practices and inadequate boundary checking that are fundamental security weaknesses in software development. These buffer overflows occur because the application fails to properly validate the length of input data before copying it into fixed-size memory buffers, creating opportunities for attackers to overwrite adjacent memory locations with malicious data.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling remote code execution, making it particularly dangerous for systems that rely on Hypermail for email archiving and retrieval. When attackers successfully exploit these buffer overflows, they can manipulate program execution flow by overwriting return addresses or function pointers in memory, potentially allowing them to inject and execute arbitrary code with the privileges of the web server process. This capability transforms a simple denial of service into a full compromise scenario where attackers can gain persistent access to the affected system. The vulnerability affects systems where Hypermail is deployed as a web-based email archiving solution, making it particularly concerning for organizations that depend on email communication infrastructure for business operations.
Mitigation strategies for this vulnerability focus on immediate patching and input validation improvements, with the most effective solution being the upgrade to Hypermail 2.1.6 or later versions that contain proper buffer size checks and input sanitization. System administrators should implement input length restrictions for attachment filenames and hostname resolution to prevent exploitation attempts, while also considering network-level protections such as firewall rules that limit access to the affected CGI programs. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow and CWE-122 Heap-based Buffer Overflow classifications, demonstrating the importance of proper memory management in preventing exploitation. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1203 Exploitation for Client Execution and T1499 Endpoint Denial of Service, emphasizing the need for comprehensive defensive measures. Organizations should also implement monitoring for unusual hostname resolution patterns and attachment filename characteristics that could indicate exploitation attempts, while maintaining regular security assessments of their email archiving systems to identify similar vulnerabilities in other components of their infrastructure.