Out-of-bounds Read Affecting kernel-tools package, versions <0:4.18.0-348.el8


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating

    Threat Intelligence

    EPSS
    0.04% (6th percentile)

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  • Snyk ID SNYK-RHEL8-KERNELTOOLS-4143170
  • published 26 Jul 2021
  • disclosed 26 May 2021

How to fix?

Upgrade RHEL:8 kernel-tools to version 0:4.18.0-348.el8 or higher.
This issue was patched in RHSA-2021:4356.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools package and not the kernel-tools package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.

CVSS Scores

version 3.1
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NVD

7.8 high
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    High
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Red Hat

7.8 high
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SUSE

8.4 high