CVE-2003-0085 in Zaurus
Summary
by MITRE
Buffer overflow in the SMB/CIFS packet fragment re-assembly code for SMB daemon (smbd) in Samba before 2.2.8, and Samba-TNG before 0.3.1, allows remote attackers to execute arbitrary code.
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Analysis
by VulDB Data Team • 04/09/2025
The vulnerability identified as CVE-2003-0085 represents a critical buffer overflow condition within the Server Message Block Common Internet File System implementation of Samba software. This flaw exists in the packet fragment re-assembly mechanism that processes incoming SMB/CIFS network requests, specifically affecting the smbd daemon component responsible for file sharing services. The vulnerability impacts versions of Samba prior to 2.2.8 and Samba-TNG prior to 0.3.1, creating a significant security risk for systems relying on these older implementations for network file sharing operations.
The technical nature of this buffer overflow stems from inadequate input validation during the re-assembly of fragmented SMB packets. When the smbd daemon receives multiple fragmented packets that together form a complete SMB message, the re-assembly code fails to properly bounds-check the data being copied into fixed-size buffers. This condition allows an attacker to craft specially malformed SMB packets that, when processed by the vulnerable daemon, cause memory corruption. The flaw manifests as a classic stack-based buffer overflow where attacker-controlled data exceeds the allocated buffer space, potentially overwriting adjacent memory locations including return addresses and function pointers.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to enable full remote code execution capabilities. Attackers exploiting this vulnerability can gain arbitrary code execution privileges on affected systems, potentially leading to complete system compromise. The attack vector requires network connectivity to the target system's SMB service port, typically TCP port 139 or 445, making it accessible to remote adversaries without requiring physical access or prior authentication. This remote exploit capability aligns with ATT&CK technique T1210 for exploiting vulnerabilities in remote services and represents a significant threat to networked environments where Samba file servers are deployed.
Systems utilizing vulnerable Samba versions face substantial risk exposure, particularly in enterprise environments where file sharing services are extensively used. The vulnerability affects organizations that have not updated their Samba implementations to versions containing the necessary patches, leaving their network infrastructure susceptible to exploitation by threat actors. Organizations running older Samba versions may be operating legacy systems or have delayed patching processes, creating extended exposure windows. The vulnerability's classification under CWE-121 indicates a stack-based buffer overflow condition that directly enables privilege escalation and arbitrary code execution.
Mitigation strategies for this vulnerability require immediate implementation of software updates to Samba versions containing the appropriate security patches. System administrators should prioritize updating all Samba installations to versions 2.2.8 or later for standard Samba releases, and 0.3.1 or later for Samba-TNG implementations. Network-level protections should include firewall rules that restrict access to SMB ports from untrusted networks, while also implementing intrusion detection systems to monitor for suspicious SMB packet patterns. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all systems running vulnerable Samba versions and establish automated patch management processes to prevent similar vulnerabilities from remaining unaddressed in future deployments.