CVE-2018-4220 in Swift
Summary
by MITRE
An issue was discovered in certain Apple products. Swift before 4.1.1 Security Update 2018-001 is affected. The issue involves the "Swift for Ubuntu" component. It allows attackers to execute arbitrary code in a privileged context because write and execute permissions are enabled during library loading.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2018-4220 affects Apple products that utilize Swift for Ubuntu, specifically versions prior to Swift 4.1.1 Security Update 2018-001. This security flaw represents a critical privilege escalation vulnerability that enables attackers to execute arbitrary code within a privileged context. The issue stems from improper permission handling during library loading processes, creating a pathway for malicious actors to gain elevated system access. The vulnerability impacts the broader Swift ecosystem on Ubuntu platforms and demonstrates the importance of secure library loading mechanisms in modern software development environments.
The technical root cause of this vulnerability lies in the library loading mechanism within Swift for Ubuntu where both write and execute permissions are simultaneously enabled during the loading process. This dangerous configuration creates a privilege escalation vector because attackers can manipulate loaded libraries to execute malicious code with elevated privileges. The flaw operates at the system level where the runtime environment fails to properly enforce separation between read, write, and execute permissions, allowing unauthorized code execution. This type of vulnerability aligns with CWE-276, which addresses improper permissions and access control issues in software systems. The specific nature of the vulnerability demonstrates how improper permission management during dynamic library loading can compromise system integrity and enable arbitrary code execution.
The operational impact of CVE-2018-4220 is significant as it allows attackers to gain unauthorized access to privileged system resources and execute malicious payloads with elevated privileges. This vulnerability affects systems running Swift for Ubuntu where attackers can leverage the improper permission handling to inject malicious code into the system. The consequences extend beyond simple code execution to include potential system compromise, data exfiltration, and further lateral movement within compromised networks. Organizations using Swift for Ubuntu platforms are particularly vulnerable as this flaw exists in the core runtime environment that applications depend upon, making it a critical target for exploitation. The vulnerability's impact is amplified by the fact that it operates at the system level rather than application level, potentially affecting multiple applications running on the same platform.
Mitigation strategies for CVE-2018-4220 focus primarily on updating to Swift 4.1.1 Security Update 2018-001 or later versions where the library loading permissions have been properly restricted. System administrators should immediately implement patch management procedures to ensure all affected Ubuntu systems running Swift are updated. Additionally, implementing proper access control measures and monitoring for unauthorized library modifications can help detect potential exploitation attempts. Security configurations should enforce strict separation of permissions during library loading processes, ensuring that write and execute permissions are not simultaneously enabled. Organizations should also consider implementing application whitelisting and runtime protection mechanisms to prevent unauthorized code execution. The vulnerability highlights the importance of following secure coding practices and adhering to the principle of least privilege, which aligns with ATT&CK technique T1068, which addresses local privilege escalation through improper permissions. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar permission-related flaws in the software ecosystem.