CVE-2010-0728 in Samba
Summary
by MITRE
smbd in Samba 3.3.11, 3.4.6, and 3.5.0, when libcap support is enabled, runs with the CAP_DAC_OVERRIDE capability, which allows remote authenticated users to bypass intended file permissions via standard filesystem operations with any client.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/02/2026
The vulnerability described in CVE-2010-0728 represents a critical privilege escalation flaw within the Samba file sharing implementation that affects multiple versions including 3.3.11, 3.4.6, and 3.5.0. This issue specifically manifests when Samba's smbd daemon operates with libcap support enabled, creating a dangerous condition where the service maintains elevated capabilities that exceed its normal operational requirements. The core problem lies in the unnecessary granting of the CAP_DAC_OVERRIDE capability, which fundamentally undermines the operating system's discretionary access control mechanisms that are designed to protect file permissions and access controls.
The technical exploitation of this vulnerability occurs through remote authenticated users who can leverage the elevated capabilities to bypass intended file permissions using standard filesystem operations. This capability allows attackers to access files and directories that should be restricted based on permission settings, effectively circumventing the security model that Samba and the underlying operating system have established. The flaw operates at the kernel level through the Linux capabilities framework, where the CAP_DAC_OVERRIDE permission specifically permits bypassing file read, write, and execute permission checks. This means that any authenticated user can perform operations that would normally be restricted by file ownership or permission bits, leading to unauthorized data access and potential system compromise.
From an operational impact perspective, this vulnerability creates a severe security risk for organizations relying on Samba for file sharing services. The remote authenticated nature of the exploit means that attackers do not need physical access to the system or local network privileges to exploit this flaw. The impact extends beyond simple file access violations as it can enable further attacks including data exfiltration, system reconnaissance, and potentially lateral movement within a network environment. The vulnerability essentially allows attackers to gain access to any file that the smbd process can access, which could include sensitive configuration files, user data, or system files that should remain protected. This represents a significant deviation from the principle of least privilege that security frameworks such as those defined in the NIST Cybersecurity Framework and ISO/IEC 27001 standards require for system security.
The mitigation strategies for this vulnerability should focus on immediate remediation through patching the affected Samba versions to eliminate the unnecessary capability assignment. Organizations should also consider implementing network segmentation to limit access to Samba services and ensure that only authorized users can authenticate to these systems. Additionally, monitoring for unusual file access patterns and implementing proper access control reviews can help detect exploitation attempts. The vulnerability aligns with ATT&CK technique T1078 for valid accounts and T1566 for phishing, as it can be exploited through legitimate authentication mechanisms. This flaw also demonstrates the importance of capability management as outlined in the Linux Security Module (LSM) framework and represents a violation of the principle of least privilege that is fundamental to secure system design. Organizations should conduct thorough security assessments to identify other services that may be incorrectly configured with excessive capabilities and ensure that all system services operate with the minimum required privileges to perform their functions.