CVE-2016-1580 in ubuntu-core-launcher
Summary
by MITRE
The setup_snappy_os_mounts function in the ubuntu-core-launcher package before 1.0.27.1 improperly determines the mount point of bind mounts when using snaps, which might allow remote attackers to obtain sensitive information or gain privileges via a snap with a name starting with "ubuntu-core."
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Analysis
by VulDB Data Team • 10/14/2024
The vulnerability identified as CVE-2016-1580 resides within the ubuntu-core-launcher package version 1.0.27.1 and earlier, specifically in the setup_snappy_os_mounts function that handles bind mount operations for snap packages. This flaw represents a critical security issue that directly impacts the integrity of the snap package system's mount point handling mechanism. The vulnerability stems from improper determination of mount points when processing bind mounts, creating a potential attack vector that could be exploited by remote adversaries to gain unauthorized access to sensitive system information or escalate privileges. The issue manifests when snap packages with names beginning with "ubuntu-core" are processed, indicating a targeted weakness in how the system handles specific naming conventions for snap packages.
The technical implementation of this vulnerability involves a flaw in the mount point resolution logic within the ubuntu-core-launcher component. When the setup_snappy_os_mounts function processes snap packages, it fails to properly validate or sanitize the mount point paths, particularly for snaps that begin with the "ubuntu-core" prefix. This improper handling allows attackers to manipulate the mount point determination process, potentially causing the system to mount filesystems in unintended locations or with incorrect permissions. The vulnerability can be exploited through the creation of malicious snap packages that leverage this naming convention to bypass normal mount point validation procedures, effectively allowing attackers to manipulate the filesystem mount hierarchy. This represents a classic case of improper input validation and path handling that could lead to privilege escalation or information disclosure.
The operational impact of CVE-2016-1580 extends beyond simple information disclosure to potentially enable privilege escalation attacks within systems running affected versions of the ubuntu-core-launcher package. Attackers could leverage this vulnerability to gain elevated privileges by manipulating how bind mounts are established for snap packages, potentially accessing system resources or sensitive data that should remain protected. The attack surface is particularly concerning because it affects the core mounting infrastructure that underpins snap package execution, meaning that successful exploitation could compromise the entire snap package ecosystem. This vulnerability directly impacts systems using Ubuntu Core or systems that rely on the ubuntu-core-launcher for managing snap package mounts, creating widespread potential for exploitation across various Ubuntu-based platforms.
Security mitigations for this vulnerability should focus on immediate package updates to version 1.0.27.1 or later, where the mount point determination logic has been corrected to properly validate and sanitize mount paths. System administrators should implement comprehensive monitoring for suspicious snap package installations, particularly those with names beginning with "ubuntu-core" or other potentially malicious naming patterns. The fix addresses the underlying CWE-785 issue related to improper handling of mount points and path resolution, which aligns with ATT&CK technique T1068 for privilege escalation through local system manipulation. Organizations should also consider implementing additional controls such as mandatory access controls and filesystem integrity monitoring to detect unauthorized mount point modifications, as this vulnerability demonstrates the critical importance of proper mount point validation in containerized and snap-based environments. The remediation process should include thorough testing of the updated package to ensure that legitimate snap package operations continue to function correctly while the security flaw is eliminated.