CVE-2017-16512 in vagrant-vmware-fusion
Summary
by MITRE
The vagrant update process in Hashicorp vagrant-vmware-fusion 5.0.2 through 5.0.4 allows local users to steal root privileges via a crafted update request when no updates are available.
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Analysis
by VulDB Data Team • 01/18/2020
The vulnerability identified as CVE-2017-16512 affects the vagrant update process within Hashicorp vagrant-vmware-fusion versions 5.0.2 through 5.0.4, representing a critical privilege escalation flaw that enables local users to escalate their privileges to root access. This vulnerability specifically manifests during the update process when no updates are available, creating a window of opportunity for malicious actors to exploit the system. The flaw resides in the update mechanism's handling of update requests, where the system fails to properly validate or sanitize incoming update data, allowing crafted requests to be processed with elevated privileges. The vulnerability directly relates to CWE-264, which addresses permissions, privileges, and access control issues, and more specifically to CWE-787, which involves out-of-bounds write vulnerabilities that can lead to privilege escalation. From an operational perspective, this vulnerability represents a significant security risk as it allows any local user to potentially gain root access without requiring authentication or elevated privileges initially. The attack vector is particularly concerning because it operates entirely within the local system context, making it difficult to detect through network monitoring and requiring no external network access. The update process in vagrant-vmware-fusion appears to execute update requests with root privileges by default, but the system does not properly validate the authenticity or integrity of these requests, creating a path for privilege escalation. This vulnerability aligns with ATT&CK technique T1068, which involves the exploitation of legitimate credentials and privileges, and T1059, which covers command and scripting interpreters, as the exploitation likely involves executing commands with elevated privileges. The impact of this vulnerability extends beyond simple privilege escalation, as it could potentially allow attackers to install malicious software, modify system files, or establish persistent access to the compromised system. The vulnerability's exploitation requires local system access but does not require network connectivity, making it particularly dangerous in environments where local access is not strictly controlled. The issue stems from the update process failing to properly validate update requests, which could include malicious payloads designed to exploit the elevated privileges granted during the update execution. This flaw essentially provides a backdoor mechanism for privilege escalation, where a local user can craft a specific update request that, when processed, executes with root privileges due to the update mechanism's design. The vulnerability's severity is amplified by the fact that vagrant-vmware-fusion is commonly used in development environments where users may have local access but the system's security controls are often less stringent than in production environments. Organizations using affected versions of vagrant-vmware-fusion should immediately implement mitigations including updating to patched versions, implementing strict access controls, and monitoring for unauthorized update requests. The vulnerability demonstrates the importance of proper input validation and privilege separation in update mechanisms, as well as the critical need for maintaining up-to-date software versions to protect against known vulnerabilities. Security teams should also consider implementing additional monitoring for update processes and privilege escalation attempts, particularly in environments where vagrant-vmware-fusion is actively used. The flaw underscores the necessity of proper security testing and validation of update mechanisms to prevent scenarios where legitimate update processes can be abused for privilege escalation purposes.