CVE-2011-3632 in Hardlink
Summary
by MITRE
Hardlink before 0.1.2 operates on full file system objects path names which can allow a local attacker to use this flaw to conduct symlink attacks.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/28/2024
The vulnerability identified as CVE-2011-3632 affects the hardlink utility version 0.1.2 and earlier, representing a significant security flaw in Unix-like operating systems. This issue stems from the utility's improper handling of file system object paths during hardlink creation operations, creating opportunities for local attackers to exploit symlink vulnerabilities. The flaw resides in the software's failure to properly validate or sanitize file paths, allowing malicious users to manipulate symbolic link references during the hardlink process. This vulnerability specifically impacts systems where the hardlink utility is used to create hard links between files, particularly in scenarios involving user-controlled or untrusted file paths.
The technical implementation of this vulnerability allows attackers to leverage the improper path handling to execute symlink attacks against the hardlink utility. When the utility processes file paths, it does not adequately check for symbolic links or resolve them properly before performing hardlink operations. This creates a race condition scenario where an attacker can replace a target file with a symbolic link during the processing window, potentially causing the hardlink utility to create links to unintended locations. The flaw essentially enables attackers to manipulate the file system structure through carefully crafted symbolic link operations, bypassing normal access controls and potentially gaining elevated privileges or access to restricted files.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it can enable attackers to manipulate file system permissions and access patterns in ways that compromise system integrity. Local attackers can exploit this vulnerability to redirect hardlink creation to arbitrary locations, potentially allowing them to modify critical system files or create backdoor access points. The attack surface is particularly concerning in multi-user environments where users might have the ability to create symbolic links in directories accessible to the hardlink utility. This vulnerability can be leveraged as part of broader attack chains, potentially enabling privilege escalation or persistent access mechanisms when combined with other local exploits. The impact is significant enough that systems running vulnerable versions of the hardlink utility should be considered compromised until properly patched.
Mitigation strategies for CVE-2011-3632 focus primarily on updating to version 0.1.2 or later of the hardlink utility where the vulnerability has been addressed through proper path validation and symbolic link handling. System administrators should implement comprehensive patch management procedures to ensure all affected systems receive the necessary updates. Additionally, access controls should be reviewed to limit the ability of untrusted users to manipulate file system structures that might be targeted by such attacks. The implementation of proper file system permissions and the use of privilege separation techniques can help reduce the potential impact of this vulnerability. Organizations should also consider monitoring for suspicious hardlink operations and implementing intrusion detection systems that can identify anomalous file system behavior. This vulnerability aligns with CWE-367, which addresses the issue of time-of-check to time-of-use race conditions, and can be mapped to ATT&CK technique T1068, which involves local privilege escalation through exploitation of system vulnerabilities. The remediation process should include verification that the patched version properly handles symbolic links and that no other similar path handling vulnerabilities exist in related system utilities.