CVE-2001-0277 in Badblue
Summary
by MITRE
Buffer overflow in ext.dll in BadBlue 1.02.07 Personal Edition allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a long HTTP GET request.
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Analysis
by VulDB Data Team • 10/07/2025
The vulnerability identified as CVE-2001-0277 represents a critical buffer overflow flaw within the ext.dll component of BadBlue 1.02.07 Personal Edition web server software. This issue manifests specifically when processing HTTP GET requests, creating a pathway for remote attackers to exploit the system through malformed input sequences. The vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient input validation allows attackers to overwrite adjacent memory locations in the program's execution stack. BadBlue was a lightweight web server software popular in the early 2000s, often used for file sharing and basic web hosting purposes on Windows systems.
The technical exploitation of this vulnerability occurs when an attacker crafts an HTTP GET request containing an excessively long string parameter that exceeds the allocated buffer space within the ext.dll module. When the web server processes this malformed request, the buffer overflow corrupts the program's execution flow by overwriting return addresses and other critical stack variables. This memory corruption can lead to two primary outcomes: denial of service through application crashes or more severe exploitation scenarios where attackers might gain arbitrary code execution privileges. The vulnerability's remote nature means that attackers do not need physical access to the system, making it particularly dangerous for publicly accessible web servers.
The operational impact of CVE-2001-0277 extends beyond simple service disruption, as the potential for arbitrary code execution creates significant security risks for affected systems. Organizations running vulnerable BadBlue installations could face complete system compromise, data theft, or use as a foothold for further network infiltration. The vulnerability's exploitation aligns with ATT&CK technique T1203, which describes exploitation of software vulnerabilities for privilege escalation and persistence. The affected environment typically includes Windows-based systems where BadBlue was installed, often in home or small office settings where proper security updates were not regularly applied. The vulnerability's age and the software's limited security updates make it particularly susceptible to exploitation by both automated tools and skilled attackers.
Mitigation strategies for this vulnerability require immediate patching or replacement of the affected BadBlue software, as no official security updates were released for this specific flaw. Organizations should implement network segmentation to limit access to vulnerable systems and deploy intrusion detection systems to monitor for suspicious HTTP GET request patterns. The recommended approach involves replacing BadBlue with modern, supported web server software such as Apache HTTP Server or Microsoft IIS, which receive regular security updates and follow current security best practices. Additionally, implementing proper input validation and buffer management techniques in web applications can prevent similar vulnerabilities from occurring in custom software development. Network administrators should also consider implementing web application firewalls and regular security audits to identify and remediate similar buffer overflow vulnerabilities across their infrastructure.