CVE-2012-4412 in C Library
Summary
by MITRE
Integer overflow in string/strcoll_l.c in the GNU C Library (aka glibc or libc6) 2.17 and earlier allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a long string, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 09/15/2024
The vulnerability identified as CVE-2012-4412 represents a critical integer overflow flaw within the GNU C Library implementation of the strcoll_l function, specifically in the string/strcoll_l.c source file. This vulnerability affects glibc versions 2.17 and earlier, where the flaw manifests during locale-aware string collation operations that process long input strings. The issue stems from inadequate input validation and overflow protection mechanisms within the library's internal string comparison routines, creating a pathway for malicious exploitation through carefully crafted input sequences. The vulnerability is classified under CWE-190 as an integer overflow condition, which occurs when an operation on signed integers exceeds the maximum representable value, leading to unexpected behavior in the system's memory management.
The technical exploitation of this vulnerability occurs when the strcoll_l function processes exceptionally long strings that trigger an integer overflow during the calculation of buffer sizes needed for string comparison operations. This overflow results in a heap-based buffer overflow condition where the system attempts to allocate memory blocks that exceed normal bounds, potentially corrupting adjacent memory regions. The flaw is context-dependent, meaning that attackers must be able to influence the input to the strcoll_l function through legitimate program interactions or by manipulating application behavior to reach the vulnerable code path. Attackers can leverage this condition to either cause system crashes through denial of service or potentially execute arbitrary code if they can control the memory layout and overwrite critical program structures.
The operational impact of CVE-2012-4412 extends beyond simple service disruption, as it can enable remote code execution in scenarios where applications using glibc are exposed to untrusted input. Systems running affected glibc versions are vulnerable to exploitation across multiple application domains since strcoll_l is a fundamental string handling function used throughout the system. The vulnerability affects not only directly running applications but also indirectly through shared library dependencies, making the attack surface significantly broader. Network services, web applications, and system utilities that perform locale-aware string operations become potential targets for exploitation, particularly in environments where user input is processed through these functions without proper sanitization. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage, as exploitation often involves manipulating string processing functions to achieve code execution.
Mitigation strategies for CVE-2012-4412 require immediate system updates to glibc versions 2.18 or later, where the integer overflow has been addressed through proper input validation and overflow checking mechanisms. System administrators should prioritize patching affected systems and conducting thorough vulnerability assessments to identify applications that may be indirectly vulnerable through shared library dependencies. Additional protective measures include implementing input length restrictions for string processing functions, deploying application firewalls to monitor for suspicious string handling patterns, and enabling address space layout randomization to complicate exploitation attempts. Regular security monitoring should focus on detecting abnormal memory allocation patterns and heap corruption indicators that may signal exploitation attempts. Organizations should also consider implementing runtime protection mechanisms such as stack canaries and heap integrity checks to provide additional defense layers against potential exploitation of similar vulnerabilities in other system components.