CVE-2021-47219

A vulnerability was found in the Linux kernel, related to the Small Computer System Interface (SCSI) subsystem. This issue involves an out-of-bounds read in the scsi_debug driver, which could allow an attacker to trigger a denial of service (DoS). This issue occurs during the handling of certain SCSI commands, leading to a system crash when invalid input lengths are passed. This vulnerability was patched in later kernel updates​.

A MODERATE severity out-of-bounds read flaw was found in the Linux kernel scsi_debug driver, in the resp_report_tgtpgs() function that handles the REPORT TARGET PORT GROUPS SCSI command. When certain SCSI commands are passed with invalid input lengths, the driver reads past the end of the allocated buffer, which can expose kernel memory contents and crash the system, resulting in a denial of service. Exploiting this flaw requires local access to a machine where the scsi_debug test/debug driver is loaded and the ability to issue SCSI commands to it; Red Hat therefore assessed it as MODERATE severity with CVSS 3.1 6.0 (AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H), whereas NIST and the CVE record assign 7.1 (Important) by rating the privileges required as low. Within Red Hat products, only the kernel and kernel-rt packages in the Red Hat Enterprise Linux 8.6 update stream are affected, and their resolution is delegated for handling; the fixing change was already included in the RHEL 8.8.z and 8.10.z update streams and in Red Hat Enterprise Linux 9, so those streams are not affected. The RHEL 6 ELS and RHEL 7 ELS kernel streams are out of support scope for this issue.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.