CVE-2012-3386 in libpng
Summary
by MITRE
The "make distcheck" rule in GNU Automake before 1.11.6 and 1.12.x before 1.12.2 grants world-writable permissions to the extraction directory, which introduces a race condition that allows local users to execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 03/26/2021
The vulnerability identified as CVE-2012-3386 resides within the GNU Automake build system utility, specifically affecting versions prior to 1.11.6 and 1.12.x before 1.12.2. This flaw manifests in the "make distcheck" rule implementation where the system creates extraction directories with world-writable permissions. The fundamental security issue stems from improper permission handling during the automated distribution checking process, which is designed to verify that software packages can be properly distributed and built. The vulnerability creates a critical race condition scenario that can be exploited by local attackers to gain elevated privileges and execute arbitrary code on the affected system.
The technical implementation of this vulnerability involves the creation of temporary directories during the distcheck process without proper permission restrictions. When GNU Automake executes the distcheck rule, it generates a temporary extraction directory that is inadvertently set with world-writable permissions, typically using chmod 0777 or equivalent. This configuration allows any local user to modify or replace files within this directory, creating a window of opportunity for malicious activity. The race condition occurs because the directory creation and permission setting happen in separate operations that can be manipulated by an attacker between the creation and the permission assignment phases. This flaw falls under CWE-732, which specifically addresses Incorrect Permission Assignment for Critical Resource, and represents a classic example of inadequate access control in system utilities.
The operational impact of CVE-2012-3386 extends beyond simple privilege escalation as it affects the integrity and security of the entire build environment. Local attackers can exploit this vulnerability to inject malicious code into the build process, potentially compromising the integrity of software packages being compiled. This risk is particularly severe in environments where automated build systems are used, as attackers could compromise the entire software supply chain. The vulnerability is classified under the MITRE ATT&CK framework as a privilege escalation technique, specifically related to "Exploitation for Privilege Escalation" and "Path Interception". The attack vector typically involves creating symbolic links or replacing files in the world-writable directory before the legitimate build process completes, allowing the attacker to execute code with the privileges of the user running make distcheck.
Mitigation strategies for this vulnerability require immediate patching of affected GNU Automake installations to versions 1.11.6 or 1.12.2 and later. Organizations should also implement proper permission auditing of build directories and enforce strict access controls on temporary file systems. System administrators should consider implementing additional security measures such as restricting the execution of make distcheck in environments where untrusted users might have access to the system. The fix implemented by the GNU Automake developers involved modifying the directory creation process to ensure proper permission settings are applied immediately upon creation, preventing the race condition from occurring. Regular security assessments of build environments and automated tools should be implemented to detect similar permission-related vulnerabilities in other system utilities and build frameworks.