CVE-2002-0133 in Avirt Gateway
Summary
by MITRE
Buffer overflows in Avirt Gateway Suite 4.2 allow remote attackers to cause a denial of service and possibly execute arbitrary code via (1) long header fields to the HTTP proxy, or (2) a long string to the telnet proxy.
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Analysis
by VulDB Data Team • 09/22/2025
The vulnerability identified as CVE-2002-0133 represents a critical buffer overflow flaw within the Avirt Gateway Suite version 4.2, specifically affecting the HTTP and telnet proxy components. This vulnerability exposes the system to remote exploitation where malicious actors can manipulate input data to trigger memory corruption conditions. The flaw manifests when the system processes incoming data through the proxy services without adequate bounds checking, allowing attackers to exceed allocated buffer space and potentially overwrite adjacent memory regions. The vulnerability operates at the application layer and can be exploited over network connections, making it particularly dangerous in networked environments where these gateways serve as intermediaries for various protocols.
The technical implementation of this vulnerability stems from improper input validation within the proxy processing modules. When the HTTP proxy receives header fields exceeding the allocated buffer size, or when the telnet proxy encounters excessively long string inputs, the system fails to perform adequate boundary checks before copying data into fixed-length memory buffers. This condition creates a classic buffer overflow scenario where attacker-controlled data can overwrite stack variables, return addresses, or other critical memory structures. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which directly aligns with the exploit methodology described in the CVE entry. The attack vectors leverage the proxy functionality to deliver malicious payloads that trigger the overflow condition, potentially leading to arbitrary code execution or system crashes.
The operational impact of CVE-2002-0133 extends beyond simple denial of service to encompass potential system compromise and unauthorized access capabilities. Remote attackers can leverage this vulnerability to cause system instability through denial of service conditions, rendering the gateway services unavailable to legitimate users. More critically, the buffer overflow condition may allow attackers to inject and execute malicious code within the system context, potentially escalating privileges and gaining unauthorized access to underlying network resources. The vulnerability affects the gateway's ability to properly process legitimate network traffic while simultaneously providing a pathway for persistent attacks that could compromise the entire network infrastructure. This vulnerability is particularly concerning as it targets gateway services that typically operate with elevated privileges and serve as critical network access points.
Mitigation strategies for CVE-2002-0133 should prioritize immediate patch deployment from the vendor, as this vulnerability was addressed through software updates that implemented proper input validation and buffer management techniques. Network administrators should implement defensive measures such as input filtering at perimeter devices, rate limiting for proxy services, and monitoring for anomalous traffic patterns that may indicate exploitation attempts. The implementation of proper bounds checking and memory management practices should be enforced throughout all proxy components to prevent similar vulnerabilities from occurring in future deployments. Security teams should also consider implementing intrusion detection systems that can identify and alert on suspicious proxy traffic patterns that may indicate exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1071.004 for application layer protocol and T1499.004 for network disruption, emphasizing the need for both defensive and detection capabilities. Organizations should also conduct thorough vulnerability assessments to identify similar buffer overflow conditions in other legacy systems and ensure comprehensive security posture maintenance across all network infrastructure components.