CVE-2000-0395 in CProxy Server
Summary
by MITRE
Buffer overflow in CProxy 3.3 allows remote users to cause a denial of service via a long HTTP request.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability identified as CVE-2000-0395 represents a classic buffer overflow flaw within CProxy 3.3, a web proxy server implementation that was widely deployed in enterprise environments during the late 1990s and early 2000s. This type of vulnerability falls under the CWE-121 category of Buffer Overflow, specifically manifesting as a stack-based buffer overflow that occurs when the application fails to properly validate input length before copying data into a fixed-size buffer. The flaw is particularly concerning because it affects a network service that typically operates with elevated privileges and serves as a critical gateway for web traffic, making it an attractive target for malicious actors seeking to disrupt network operations.
The technical mechanism of this vulnerability involves the CProxy 3.3 application's handling of HTTP requests where it fails to properly check the length of incoming data before copying it into internal buffers. When a remote attacker crafts a specially formatted HTTP request containing an excessive amount of data in headers or other request components, the application's buffer management routines overflow, causing unpredictable behavior in the application's execution flow. This overflow can result in the corruption of adjacent memory locations, potentially leading to application crashes or in more severe cases, allowing for arbitrary code execution if the overflow is carefully crafted. The vulnerability is classified as a remote attack vector since no local access is required to exploit it, making it particularly dangerous in networked environments where the proxy server is accessible to untrusted users.
The operational impact of this vulnerability extends beyond simple denial of service, as it can severely compromise the availability and integrity of web services that depend on the affected proxy server. Organizations utilizing CProxy 3.3 in their infrastructure would experience complete disruption of web access when the vulnerability is exploited, potentially affecting hundreds or thousands of users depending on the scale of deployment. The attack surface is particularly broad since proxy servers typically serve as the primary gateway for internet access within corporate networks, making them attractive targets for attackers seeking to gain control over network access. This vulnerability aligns with ATT&CK technique T1499.004 for Network Denial of Service and demonstrates how seemingly minor input validation flaws can have catastrophic operational consequences.
Mitigation strategies for CVE-2000-0395 should focus on immediate patching of the affected CProxy 3.3 installation, as the vendor likely released a security update addressing the buffer overflow in subsequent versions. Organizations should implement network segmentation to limit access to proxy servers and deploy intrusion detection systems to monitor for suspicious HTTP request patterns that might indicate exploitation attempts. Input validation mechanisms should be strengthened at the application level by implementing proper bounds checking and length validation for all incoming HTTP request data. Additionally, network administrators should consider implementing rate limiting and request size restrictions to prevent exploitation attempts from overwhelming the proxy server with malformed requests, which aligns with defensive techniques described in MITRE ATT&CK framework for preventing privilege escalation and maintaining system availability.