CVE-2011-2168 in OpenBSD
Summary
by MITRE
Multiple integer overflows in the glob implementation in libc in OpenBSD before 4.9 might allow context-dependent attackers to have an unspecified impact via a crafted string, related to the GLOB_APPEND and GLOB_DOOFFS flags, a different issue than CVE-2011-0418.
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Analysis
by VulDB Data Team • 03/23/2015
The vulnerability identified as CVE-2011-2168 represents a critical integer overflow flaw within the glob implementation of OpenBSD's libc library prior to version 4.9. This issue specifically affects the handling of crafted strings when utilizing the GLOB_APPEND and GLOB_DOOFFS flags during glob pattern matching operations. The vulnerability falls under the category of software defects that can lead to unpredictable behavior and potential security exploitation, with implications that extend beyond simple denial of service to potentially enabling arbitrary code execution or privilege escalation.
The technical flaw manifests as integer overflows occurring during the processing of glob patterns when these specific flags are employed. When a maliciously crafted string is passed to the glob function with GLOB_APPEND or GLOB_DOOFFS flags, the internal integer calculations used to determine memory allocation or buffer boundaries can overflow, resulting in incorrect memory management decisions. This overflow condition creates opportunities for attackers to manipulate memory layout and potentially execute malicious code. The vulnerability is particularly concerning because it operates in a context-dependent manner, meaning the impact varies based on the specific environment and input conditions present during execution.
From an operational impact perspective, this vulnerability presents significant risks to systems running affected versions of OpenBSD. The unspecified impact mentioned in the CVE description indicates that exploitation could potentially lead to various security consequences including but not limited to privilege escalation, arbitrary code execution, or system compromise. The context-dependent nature of the vulnerability means that attackers must carefully craft inputs to exploit the integer overflow, but once successful, the consequences can be severe. This type of vulnerability is particularly dangerous in server environments where glob pattern matching might be used with untrusted input from network sources or user-supplied data.
The vulnerability aligns with CWE-190, which identifies integer overflow and underflow as a common class of software defects that can lead to security vulnerabilities. Additionally, this issue demonstrates characteristics consistent with ATT&CK technique T1059.007, where adversaries may leverage command and control communications through the use of glob patterns that can be exploited to manipulate system behavior. Organizations should prioritize patching affected systems, as the integer overflow conditions can be exploited to gain unauthorized access to systems or escalate privileges. System administrators should implement monitoring for unusual glob pattern usage and consider implementing input validation measures to prevent malformed strings from reaching the vulnerable code paths. The remediation strategy should focus on upgrading to OpenBSD version 4.9 or later, where the integer overflow conditions have been properly addressed through improved input validation and memory management within the glob implementation.