CVE-2001-0207 in Bing
Summary
by MITRE
Buffer overflow in bing allows remote attackers to execute arbitrary commands via a long hostname, which is copied to a small buffer after a reverse DNS lookup using the gethostbyaddr function.
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Analysis
by VulDB Data Team • 07/03/2014
The vulnerability described in CVE-2001-0207 represents a classic buffer overflow flaw within the bing service that enables remote code execution through malformed hostname inputs. This issue stems from inadequate input validation during reverse DNS lookup operations, specifically when the gethostbyaddr function processes excessively long hostnames. The bing service, which typically handles network connections and service requests, fails to properly constrain the size of hostname data received during the reverse DNS resolution process, creating an exploitable condition that can be leveraged by remote attackers.
The technical mechanism behind this vulnerability involves the exploitation of a stack-based buffer overflow occurring during reverse DNS resolution. When a client connects to the bing service and provides a hostname for reverse lookup, the system performs a gethostbyaddr operation that copies the resolved hostname into a fixed-size buffer. This buffer, intentionally small to conserve memory, cannot accommodate excessively long hostname strings that exceed its allocated capacity. The overflow occurs because the system does not validate the length of the hostname data before copying it to the limited buffer space, allowing maliciously crafted inputs to overwrite adjacent memory locations including return addresses and control data structures.
The operational impact of this vulnerability extends beyond simple service disruption to encompass full system compromise. Remote attackers can leverage this buffer overflow to execute arbitrary code with the privileges of the bing service process, potentially leading to complete system takeover. The vulnerability affects systems running the bing service across various unix-like operating systems and can be exploited from remote locations without requiring authentication. Successful exploitation can result in unauthorized access to sensitive data, privilege escalation, and establishment of persistent backdoors within affected networks. This makes the vulnerability particularly dangerous in enterprise environments where bing services may be exposed to untrusted networks.
Mitigation strategies for CVE-2001-0207 should focus on both immediate patching and defensive measures. The primary solution involves applying vendor-specific patches that implement proper input validation and buffer size checking for hostname data during reverse DNS lookups. System administrators should also implement network-level restrictions such as firewall rules that limit access to bing services from untrusted sources. Additionally, implementing proper input sanitization techniques including length validation, boundary checking, and secure coding practices can prevent similar vulnerabilities from manifesting in other applications. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and corresponds to attack patterns in the MITRE ATT&CK framework under privilege escalation and remote code execution tactics. Organizations should also consider implementing intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability class.