CVE-2017-13314 in Android
Summary
by MITRE • 11/16/2024
In setAllowOnlyVpnForUids of NetworkManagementService.java, there is a possible security settings bypass due to a missing permission check. This could lead to local escalation of privilege allowing users to access non-VPN networks, when they are supposed to be restricted to the VPN networks, with no additional execution privileges needed. User interaction is not needed for exploitation.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/18/2024
The vulnerability identified as CVE-2017-13314 resides within the NetworkManagementService.java component of Android systems, specifically in the setAllowOnlyVpnForUids method. This flaw represents a critical security configuration oversight that undermines the fundamental network isolation principles designed to protect users within VPN environments. The vulnerability stems from the absence of proper permission validation within the method implementation, creating a pathway for unauthorized access to non-VPN network resources despite explicit restrictions.
The technical implementation flaw manifests as a missing permission check that should validate whether the calling process possesses adequate privileges before modifying VPN network access controls. This absence allows any malicious application or process to bypass the intended network restrictions by manipulating the VPN configuration parameters. The vulnerability operates at the system level where network management services are responsible for enforcing security policies, making it particularly dangerous as it can be exploited without requiring any user interaction or additional privileges beyond what is already available to the malicious actor.
From an operational impact perspective, this vulnerability enables local privilege escalation by allowing attackers to circumvent network access controls that are specifically designed to prevent unauthorized network access. When users are configured to access only VPN networks, this vulnerability permits them to access all network resources including non-VPN connections, effectively nullifying the security controls that protect against unauthorized network access. The implications extend beyond simple network access, as it can enable data exfiltration, lateral movement, and other malicious activities that rely on maintaining network isolation boundaries.
The vulnerability aligns with CWE-284, which addresses improper access control in software implementations, specifically focusing on missing permission checks that allow unauthorized access to protected resources. From an adversarial perspective, this flaw maps directly to ATT&CK technique T1068, which involves the use of local privilege escalation techniques to gain elevated system access. The absence of user interaction requirements makes this vulnerability particularly attractive to attackers as it can be exploited automatically without requiring any form of social engineering or user engagement.
Mitigation strategies should focus on implementing proper permission validation within the setAllowOnlyVpnForUids method, ensuring that only authorized system processes can modify VPN network restrictions. This includes enforcing strict access controls and validating the calling process permissions before allowing any modifications to network access policies. Additionally, system administrators should ensure that devices are updated with patches that address this specific vulnerability, as the flaw exists in the core network management service implementation. The remediation process should also include monitoring for unauthorized network access attempts and implementing additional security controls to prevent exploitation of similar permission bypass vulnerabilities in other system components.