CVE-2018-16874 in Google
Summary
by MITRE
In Go before 1.10.6 and 1.11.x before 1.11.3, the "go get" command is vulnerable to directory traversal when executed with the import path of a malicious Go package which contains curly braces (both '{' and '}' characters). Specifically, it is only vulnerable in GOPATH mode, but not in module mode (the distinction is documented at https://golang.org/cmd/go/#hdr-Module_aware_go_get). The attacker can cause an arbitrary filesystem write, which can lead to code execution.
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Analysis
by VulDB Data Team • 06/19/2023
The vulnerability CVE-2018-16874 represents a critical directory traversal flaw in the go get command of the Go programming language ecosystem. This vulnerability affects Go versions prior to 1.10.6 and 1.11.3, specifically manifesting in GOPATH mode where the command processes import paths containing curly braces. The flaw stems from inadequate input validation and path handling within the package retrieval mechanism, creating a pathway for malicious actors to manipulate filesystem operations through carefully crafted package names. The vulnerability operates under CWE-22, which categorizes directory traversal attacks as a fundamental security weakness in input validation and path handling. This weakness allows attackers to bypass normal access controls and potentially execute arbitrary code on the target system.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious Go package with import paths containing curly braces, which the go get command interprets incorrectly during the package resolution process. In GOPATH mode, the command fails to properly sanitize these special characters, leading to improper path construction that can result in arbitrary filesystem writes. The attack vector specifically targets the GOPATH environment where Go manages dependencies, making it particularly dangerous for developers who rely on automated package retrieval. When the go get command processes such malformed import paths, it can traverse directories beyond its intended scope and write files to locations specified by the attacker, potentially overwriting critical system files or injecting malicious code. This behavior aligns with ATT&CK technique T1059.001 for command and scripting interpreter usage and T1078.004 for valid accounts, as the attack leverages legitimate system operations to achieve unauthorized file system access.
The operational impact of this vulnerability extends beyond simple directory traversal, as it can lead to complete system compromise through code execution. An attacker who successfully exploits this vulnerability can inject malicious code into the target system, potentially gaining persistent access or escalating privileges. The vulnerability is particularly concerning in development environments where developers frequently use go get to retrieve third-party packages, as it can be exploited through seemingly legitimate package installations. Organizations using older Go versions in GOPATH mode face significant risk, as the vulnerability can be triggered by any package containing curly braces in its import path. The attack requires minimal privileges and can be executed through standard package management workflows, making it a high-impact vulnerability for development teams and security administrators.
Mitigation strategies for CVE-2018-16874 primarily focus on upgrading to patched versions of Go where the vulnerability has been addressed through improved input validation and path handling. Organizations should immediately update their Go installations to versions 1.10.6 or later, or 1.11.3 and later, depending on their current version. Additionally, developers should avoid using go get with untrusted packages and consider implementing additional security measures such as package signature verification and dependency whitelisting. The vulnerability highlights the importance of secure coding practices in package management systems and underscores the need for robust input validation in all system components that handle user-provided data. Security teams should also monitor for potential exploitation attempts and implement network-based detection measures to identify suspicious package retrieval activities. The remediation process should include comprehensive testing to ensure that the upgrade does not introduce compatibility issues with existing development workflows and that proper module mode usage is enforced to prevent future vulnerabilities.