Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability was identified in the Linux kernel's handling of SCSI Response data over TCP, where an oversized response could lead to a buffer overflow. This could potentially allow for a denial-of-service or even impact system integrity, depending on how the overflow is triggered and what data is affected.
- A Linux kernel flaw can cause system issues.
- It could allow unauthorized data access or disruption.
- Confirm relevance and exposure for iSCSI TCP.
Attack Path
How an attacker could exploit the issue
An attacker could exploit this vulnerability by sending specially crafted SCSI responses over a network to a Linux system running a vulnerable iSCSI target. This could occur if the iSCSI target's advertised maximum data segment length is negotiated to be significantly larger than the buffer allocated for responses. When the vulnerable `iscsi_tcp_hdr_dissect()` function processes a `SCSI_CMD_RSP` PDU with a large data segment, it can overflow a fixed-size buffer, potentially leading to a denial-of-service or information disclosure.
- Network exposure required.
- Overflow fixed-size buffer with large data.
- Potential for denial-of-service or information disclosure.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability could affect system data by allowing a target to send an oversized SCSI Response, leading to a buffer overflow when the Linux kernel's iSCSI TCP implementation processes this data. This overflow occurs when the DataSegmentLength of a SCSI Response exceeds the fixed-size connection data buffer, and the system's checks are bypassed.
- System memory could be corrupted.
- An attacker could trigger a buffer overflow.
- Denial of service is a potential outcome.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability impacts the Linux kernel's iSCSI TCP implementation, specifically how it handles SCSI Command Response data. In a real-world scenario, the teams responsible for storage infrastructure, kernel modules, and potentially the application owners leveraging iSCSI would need to coordinate. The first practical step involves identifying all systems running the affected kernel version, determining their exposure to untrusted network segments, and confirming their business criticality before planning remediation actions.
- Storage and kernel teams own this issue.
- Verify iSCSI network exposure and criticality.
- Plan and execute kernel updates.
