CVE-2012-5667 in grep
Summary
by MITRE
Multiple integer overflows in GNU Grep before 2.11 might allow context-dependent attackers to execute arbitrary code via vectors involving a long input line that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 06/13/2024
The vulnerability identified as CVE-2012-5667 represents a critical security flaw in GNU Grep versions prior to 2.11, specifically targeting integer overflow conditions that can lead to arbitrary code execution. This vulnerability exists within the core processing logic of the grep utility, which is widely used for pattern matching in text files across Unix-like operating systems and Linux distributions. The flaw manifests when processing input lines of excessive length, creating conditions where integer arithmetic operations overflow and subsequently trigger heap-based buffer overflow conditions that attackers can exploit for malicious purposes.
The technical implementation of this vulnerability stems from improper handling of integer values during memory allocation calculations within grep's internal processing functions. When grep encounters input lines that exceed certain length thresholds, the integer variables used to calculate buffer sizes become overflowed, resulting in insufficient memory allocation for the actual data processing. This integer overflow condition creates a heap-based buffer overflow scenario where attacker-controlled data can overwrite adjacent memory regions, potentially allowing for code execution. The vulnerability is context-dependent, meaning it requires specific input conditions to be triggered, making it more challenging to exploit but still highly dangerous in environments where grep is used for processing untrusted input.
The operational impact of CVE-2012-5667 extends across numerous system administration and security contexts where grep functionality is utilized. Systems that process user input through grep commands, including web applications, log processing pipelines, and automated security tools, become vulnerable to remote code execution attacks. This vulnerability particularly affects environments where grep is used in conjunction with other utilities or in automated scripts that process potentially malicious input. The exploitability of this vulnerability is enhanced in scenarios where grep is executed with elevated privileges or in contexts where input validation is insufficient. The integer overflow occurs during the processing of long input lines, making it particularly relevant for systems that handle large data sets or are exposed to untrusted input streams.
Mitigation strategies for this vulnerability center around immediate patching of GNU Grep installations to version 2.11 or later, which contains the necessary fixes for the integer overflow conditions. System administrators should also implement input validation measures to limit the length of text processed by grep commands, particularly in applications that process user-supplied data. Additional protective measures include running grep in restricted environments with limited privileges, implementing proper memory management checks, and monitoring for unusual grep execution patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and represents a typical example of how integer arithmetic errors can lead to memory corruption vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to techniques involving code injection and privilege escalation, as the heap-based buffer overflow can potentially be leveraged to execute arbitrary code with the privileges of the grep process. Organizations should also consider implementing application whitelisting policies that restrict the execution of potentially vulnerable versions of grep, while maintaining regular vulnerability assessments to identify similar integer overflow conditions in other system utilities.