CVE-2012-0194 in AIX
Summary
by MITRE
The TCP implementation in IBM AIX 5.3, 6.1, and 7.1, when the Large Send Offload option is enabled, allows remote attackers to cause a denial of service (assertion failure and panic) via an unspecified series of packets.
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2012-0194 represents a critical flaw in the Transmission Control Protocol implementation within IBM AIX operating systems across multiple versions including 5.3, 6.1, and 7.1. This weakness specifically manifests when the Large Send Offload feature is enabled, creating a pathway for remote attackers to execute denial of service attacks that can result in system crashes and complete system panics. The vulnerability stems from inadequate validation mechanisms within the TCP stack that fail to properly handle certain packet sequences, leading to assertion failures that ultimately cause system instability and potential service interruption.
The technical implementation of this vulnerability lies within the TCP offload engine's handling of network packets when Large Send Offload is active. This feature is designed to improve network performance by allowing the network adapter to handle the segmentation of large packets, but the flaw occurs during packet processing when the system encounters specific combinations of packet headers and data sequences. The assertion failure indicates that the TCP implementation contains internal checks that are triggered by malformed packet sequences, causing the kernel to terminate unexpectedly and resulting in system panic conditions. This type of vulnerability maps directly to CWE-129, which addresses improper validation of input boundaries, and CWE-131, which covers incorrect calculation of buffer or data sizes.
The operational impact of CVE-2012-0194 extends beyond simple service disruption to encompass complete system compromise and availability loss for affected IBM AIX installations. Remote attackers can exploit this vulnerability without requiring authentication or privileged access, making it particularly dangerous in networked environments where systems may be exposed to untrusted network traffic. When successfully exploited, the vulnerability can cause complete system crashes requiring manual intervention and system restarts, potentially leading to extended downtime and service interruption for critical business applications. The attack vector is particularly concerning because it can be executed over standard network connections without requiring specialized tools or conditions, making it accessible to a broad range of threat actors.
Organizations running affected IBM AIX versions should implement immediate mitigations including disabling the Large Send Offload feature when possible, as this directly addresses the vulnerability condition. System administrators should also consider implementing network segmentation and access controls to limit exposure to potentially malicious traffic. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how network protocol implementations can contain critical flaws that affect system stability and availability. Regular security updates and patches from IBM should be prioritized to address this vulnerability, as the flaw exists in multiple versions of the operating system and requires vendor-specific remediation rather than generic network security measures.