CVE-2015-0796 in Open Build Service
Summary
by MITRE
In open buildservice 2.6 before 2.6.3, 2.5 before 2.5.7 and 2.4 before 2.4.8 the source service patch application could generate non-standard files like symlinks or device nodes, which could allow buildservice users to break of confinement or cause denial of service attacks on the source service.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/16/2023
The vulnerability identified as CVE-2015-0796 affects the open buildservice software version 2.6 before 2.6.3, 2.5 before 2.5.7, and 2.4 before 2.4.8. This represents a significant security flaw in the source service patch application mechanism that forms part of the build process for software packages within the open buildservice environment. The issue stems from inadequate validation and sanitization of patch files during the application process, creating a pathway for malicious or unintended file creation that can compromise system integrity and availability.
The technical flaw manifests when the source service patch application processes patch files that contain non-standard file types such as symbolic links or device nodes. These file types are not typically generated during normal patch application operations and represent a deviation from expected behavior. The vulnerability allows attackers to inject these special file types into the build environment through crafted patch files, which can then be processed by the buildservice. This creates a potential for privilege escalation or system compromise as these special files can be used to manipulate the build environment in unexpected ways. The flaw directly relates to CWE-22, which addresses improper limitation of a pathname to a restricted directory, and CWE-264, which covers permissions, privileges, and access controls, as the vulnerability enables unauthorized file creation and manipulation.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable more serious compromise scenarios. When the buildservice processes patches containing symbolic links or device nodes, it can create these special files within the build environment, which may allow users to break out of confinement mechanisms that are designed to isolate build processes. This confinement breaking capability can lead to unauthorized access to system resources, data exposure, or the ability to execute arbitrary code within the build environment. The vulnerability essentially undermines the security boundaries that protect the buildservice infrastructure from malicious inputs, creating opportunities for attackers to escalate privileges or cause system instability through carefully crafted patch files that generate non-standard file types during the patch application process.
Mitigation strategies for this vulnerability should focus on implementing strict input validation and sanitization of patch files before they are processed by the source service. The most effective approach involves updating to the patched versions of open buildservice 2.6.3, 2.5.7, and 2.4.8 where the patch application mechanism has been enhanced to reject or properly handle non-standard file types. Organizations should also implement additional security controls such as restricting patch file sources, implementing file type whitelisting for patch content, and monitoring build service operations for unusual file creation patterns. From an operational security perspective, this vulnerability aligns with ATT&CK technique T1059 for execution through command and scripting interpreter, and T1078 for valid accounts, as it can potentially be exploited through compromised build service accounts or by manipulating the build process itself. The vulnerability also represents a failure in the principle of least privilege, as users should not be able to create special file types that could compromise system integrity. Regular security assessments of build environments and patch management processes should be implemented to prevent similar vulnerabilities from emerging in other components of the software supply chain.