CVE-2011-3631 in Hardlink
Summary
by MITRE
Hardlink before 0.1.2 has multiple integer overflows leading to heap-based buffer overflows because of the way string lengths concatenation is done in the calculation of the required memory space to be used. A remote attacker could provide a specially-crafted directory tree and trick the local user into consolidating it, leading to hardlink executable crash or potentially arbitrary code execution with user privileges.
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Analysis
by VulDB Data Team • 02/27/2024
The vulnerability identified as CVE-2011-3631 resides within the hardlink utility version 0.1.1 and earlier, presenting a critical security flaw that stems from improper handling of string length calculations during memory allocation processes. This issue manifests as multiple integer overflows that ultimately result in heap-based buffer overflows, creating a significant attack surface for malicious actors. The vulnerability specifically occurs during the concatenation of string lengths when calculating the required memory space for processing directory trees, demonstrating a fundamental flaw in input validation and memory management practices.
The technical implementation of this vulnerability involves the hardlink utility's failure to properly validate or sanitize string length parameters before performing arithmetic operations that determine memory allocation sizes. When processing directory structures, the application concatenates various string components to calculate total memory requirements, but due to integer overflow conditions, the calculated memory space becomes insufficient or excessive, leading to buffer overflow scenarios. This memory corruption occurs in the heap memory region, making it particularly dangerous as it can be exploited to overwrite critical program data or execution control structures.
From an operational perspective, this vulnerability creates a sophisticated attack vector that requires social engineering to execute successfully. The remote attacker must craft a specially designed directory tree structure that, when consolidated by a local user, triggers the vulnerable code path. The attack scenario typically involves tricking users into executing the hardlink utility with maliciously constructed directory hierarchies, making this a privilege escalation vulnerability that operates at the user level. The potential impact extends beyond simple application crashes, as successful exploitation could lead to arbitrary code execution with the privileges of the compromised user account, representing a significant compromise of system integrity.
The vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and demonstrates characteristics consistent with CWE-122, heap-based buffer overflow vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and execution through legitimate system tools, particularly T1059.1 for command and scripting interpreter and T1068 for local privilege escalation. The attack chain requires the initial compromise through social engineering to convince users to execute the vulnerable utility, followed by the exploitation of the heap overflow to gain code execution capabilities.
Mitigation strategies for this vulnerability should prioritize immediate patching of the hardlink utility to version 0.1.2 or later, which contains the necessary fixes for integer overflow handling and proper memory allocation calculations. System administrators should also implement strict file permission controls and monitor for unauthorized execution of the hardlink utility, particularly in environments where users have elevated privileges. Additionally, deploying runtime application protection mechanisms and implementing input sanitization measures can provide defense-in-depth protection against similar vulnerabilities in other applications. Organizations should conduct comprehensive vulnerability assessments to identify other instances of similar integer overflow patterns within their software inventory, as this represents a common class of memory corruption vulnerabilities that require careful attention to proper integer handling and bounds checking throughout the codebase.