CVE-2012-3368 in dtach
Summary
by MITRE
Integer signedness error in attach.c in dtach 0.8 allows remote attackers to obtain sensitive information from daemon stack memory in opportunistic circumstances by reading application data after an improper connection-close request, as demonstrated by running an IRC client in dtach.
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Analysis
by VulDB Data Team • 12/05/2021
The vulnerability identified as CVE-2012-3368 represents a critical integer signedness error within the dtach terminal multiplexer version 0.8, specifically within the attach.c component. This flaw arises from improper handling of signed and unsigned integer comparisons during connection management operations. The issue manifests when dtach processes connection-close requests, creating a scenario where memory access patterns become unpredictable and potentially exploitable. The vulnerability is particularly concerning because it allows remote attackers to extract sensitive information from the daemon's stack memory through opportunistic read operations that occur after improper connection termination.
The technical root cause of this vulnerability stems from a fundamental flaw in how dtach handles integer values during socket connection management. When a connection is closed improperly, the application fails to properly validate the signedness of integer values used in memory allocation and data handling operations. This creates a condition where unsigned integers may be interpreted as signed values, leading to incorrect memory boundaries and access patterns. The flaw is classified under CWE-190 as an integer overflow or wraparound, specifically manifesting as an integer signedness error that allows for memory corruption conditions. The vulnerability operates through a classic buffer over-read scenario where the application attempts to read beyond allocated memory boundaries, potentially exposing stack contents including sensitive data such as authentication tokens, session information, or other confidential application data.
The operational impact of CVE-2012-3368 extends beyond simple information disclosure, as it creates a potential attack vector that could be exploited in conjunction with other techniques to compromise system security. The demonstration using IRC clients highlights the practical implications of this vulnerability, as it shows how attackers could potentially intercept sensitive communication data while users are operating applications within dtach sessions. This type of vulnerability aligns with ATT&CK technique T1005 as it involves data from local system enumeration, and T1059 for execution of malicious code through application interfaces. The opportunistic nature of the exploit means that attackers do not require sophisticated conditions to trigger the vulnerability, making it particularly dangerous in environments where dtach is used to manage multiple user sessions or where sensitive data flows through terminal multiplexer applications.
Mitigation strategies for this vulnerability must address both the immediate code-level issues and broader security practices within terminal multiplexer implementations. The primary fix involves correcting the integer signedness handling in the attach.c file to ensure proper validation of signed and unsigned integer operations during connection management. Security practitioners should implement input validation measures that prevent improper connection termination sequences from creating memory access violations. Additionally, the vulnerability demonstrates the importance of memory safety practices and proper error handling in daemon applications. Organizations should consider implementing network segmentation and access controls to limit exposure, while also ensuring that all terminal multiplexer implementations are updated to versions that address this specific integer signedness error. The fix should include comprehensive testing to validate that all integer comparisons and memory access patterns properly handle signed and unsigned values according to established security standards and best practices.