CVE-2003-0196 in Samba
Summary
by MITRE
Multiple buffer overflows in Samba before 2.2.8a may allow remote attackers to execute arbitrary code or cause a denial of service, as discovered by the Samba team and a different vulnerability than CVE-2003-0201.
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Analysis
by VulDB Data Team • 05/10/2019
The vulnerability identified as CVE-2003-0196 represents a critical security flaw affecting Samba versions prior to 2.2.8a, exposing systems to potential remote code execution and denial of service attacks. This vulnerability was discovered by the Samba development team and distinct from the related CVE-2003-0201, highlighting the complexity of buffer overflow issues within network services. The flaw manifests in multiple buffer overflows that can be exploited by remote attackers without authentication, making it particularly dangerous for networked environments where Samba servers are deployed. These buffer overflows occur in the server-side processing of network requests, specifically in the handling of SMB (Server Message Block) protocol communications that Samba uses for file and printer sharing services. The vulnerability is categorized under CWE-121 as stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations, potentially leading to arbitrary code execution.
The technical implementation of this vulnerability involves the improper handling of input data within Samba's SMB protocol processing functions. When remote attackers send specially crafted network packets containing malformed data, the server fails to properly validate buffer boundaries, allowing attackers to overwrite critical memory areas including return addresses and function pointers. This memory corruption can be leveraged to redirect program execution flow, enabling attackers to inject and execute malicious code on the target system. The impact extends beyond simple code execution to include denial of service conditions, where carefully constructed inputs can crash the Samba service and render it unavailable to legitimate users. The vulnerability affects the core SMB protocol implementation and impacts all Samba versions up to and including 2.2.8a, making it a widespread concern for organizations relying on Samba for network file sharing.
From an operational perspective, the exploitation of CVE-2003-0196 poses significant risks to enterprise networks where Samba servers function as file shares, print servers, or domain controllers. The remote nature of the attack means that adversaries can exploit these vulnerabilities from outside the network perimeter, potentially gaining unauthorized access to sensitive data and system resources. The vulnerability aligns with ATT&CK technique T1190 for exploiting vulnerabilities in network protocols, specifically targeting the SMB service that many organizations depend upon for file sharing and authentication. Organizations running affected Samba versions face potential data breaches, service disruptions, and complete system compromise, making immediate remediation essential for network security. The vulnerability's impact is amplified in environments where Samba servers are exposed to the internet or where multiple services are hosted on the same infrastructure, creating additional attack vectors for threat actors.
The recommended mitigation strategy for CVE-2003-0196 involves immediate deployment of Samba version 2.2.8a or later, which contains the necessary patches to address the buffer overflow conditions. Network administrators should implement firewall rules to restrict access to Samba ports, particularly TCP ports 139 and 445, limiting exposure to unauthorized networks. Additionally, organizations should conduct thorough vulnerability assessments to identify all systems running affected Samba versions and prioritize patching efforts accordingly. The mitigation approach should also include monitoring network traffic for suspicious activity related to SMB protocol exploitation attempts and implementing intrusion detection systems to detect potential exploitation attempts. Regular security updates and patch management processes should be established to prevent similar vulnerabilities from being introduced in the future. Organizations may also consider implementing network segmentation to isolate Samba services from critical network segments and employ additional security controls such as host-based firewalls and access control lists to further reduce the attack surface. The vulnerability serves as a reminder of the importance of maintaining current security patches and the critical need for continuous monitoring of network services for potential exploitation attempts.