NULL Pointer Dereference Affecting kernel-cross-headers package, versions <0:4.18.0-193.1.2.el8_2


Severity

Recommended
high

Based on Red Hat Enterprise Linux security rating

    Threat Intelligence

    EPSS
    0.8% (83rd percentile)

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  • Snyk ID SNYK-RHEL8-KERNELCROSSHEADERS-3756458
  • published 26 Jul 2021
  • disclosed 12 May 2020

How to fix?

Upgrade RHEL:8 kernel-cross-headers to version 0:4.18.0-193.1.2.el8_2 or higher.
This issue was patched in RHSA-2020:2102.

NVD Description

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

A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service.

CVSS Scores

version 3.1
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NVD

5.9 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    None
  • Availability (A)
    High
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Red Hat

5.9 medium
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SUSE

5.9 medium