CVE-2003-1186 in Simplewebserver
Summary
by MITRE
Buffer overflow in TelCondex SimpleWebServer 2.12.30210 Build3285 allows remote attackers to execute arbitrary code via a long HTTP Referer header.
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Analysis
by VulDB Data Team • 06/20/2019
The vulnerability identified as CVE-2003-1186 represents a critical buffer overflow flaw within the TelCondex SimpleWebServer version 2.12.30210 Build3285. This web server implementation suffers from inadequate input validation mechanisms that fail to properly sanitize the HTTP Referer header field. The flaw arises from the server's insufficient bounds checking when processing incoming HTTP requests, specifically targeting the Referer header parameter which is commonly used by web browsers to indicate the address of the page making the request. The vulnerability exists in the server's parsing logic where it allocates a fixed-size buffer to store the Referer header content without verifying that the incoming data length exceeds the allocated memory space.
The technical exploitation of this buffer overflow vulnerability enables remote attackers to overwrite adjacent memory locations within the SimpleWebServer process. When an attacker crafts a malicious HTTP request containing an excessively long Referer header value, the server's memory management routines fail to prevent the overflow condition. This condition allows the attacker to potentially overwrite critical program variables, return addresses, or function pointers in the call stack, ultimately enabling arbitrary code execution within the context of the web server process. The vulnerability manifests as a classic stack-based buffer overflow scenario where the attacker can control the execution flow of the vulnerable application through careful manipulation of the input data.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with persistent access to the affected system. Once successfully exploited, the attacker gains the ability to execute malicious code with the privileges of the web server process, which typically runs with elevated permissions on the host system. This access can lead to complete system compromise, data exfiltration, or the establishment of backdoors for continued unauthorized access. The vulnerability affects any system running the specific version of TelCondex SimpleWebServer, making it particularly dangerous in environments where legacy web server implementations are still in use. The exploitability of this vulnerability is relatively straightforward, requiring only the ability to send HTTP requests to the target server, making it a significant threat in both internal network environments and public-facing web services.
Mitigation strategies for CVE-2003-1186 should prioritize immediate patching of the affected SimpleWebServer version, as this represents the most effective solution to eliminate the vulnerability. Organizations should implement network-level controls such as firewall rules that restrict access to the web server port and monitor for suspicious Referer header patterns in network traffic logs. Input validation mechanisms should be implemented at the application level to enforce maximum length limits on HTTP headers, particularly the Referer field. Security monitoring systems should be configured to detect and alert on unusually long HTTP header values that may indicate attempted exploitation. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow and demonstrates characteristics consistent with techniques described in the ATT&CK framework under the T1203 Exploitation for Client Execution tactic. Regular security assessments and vulnerability scanning should be conducted to identify other potential buffer overflow vulnerabilities in legacy web server implementations, as this particular flaw highlights the importance of proper input validation and memory management in network services.