CVE-2024-43893

Public on

Last Modified: UTC

Description

A divide by zero vulnerability was found in the uart_get_divisor() function in the Linux Kernel's serial core subsystem. This issue is caused by the improper handling of invalid baud rates. When an invalid baud_base is specified using the TIOCSSERIAL ioctl command, if uartclk is zero, a subsequent call to uart_get_divisor() results in a divide by zero error. A local attacker could exploit this vulnerability by issuing a specially crafted TIOCSSERIAL ioctl call with an invalid baud_base value. This could cause a divide by zero error, leading to a kernel crash and denial of service.

A divide by zero vulnerability was found in the uart_get_divisor() function in the Linux Kernel's serial core subsystem. This issue is caused by the improper handling of invalid baud rates. When an invalid baud_base is specified using the TIOCSSERIAL ioctl command, if uartclk is zero, a subsequent call to uart_get_divisor() results in a divide by zero error. A local attacker could exploit this vulnerability by issuing a specially crafted TIOCSSERIAL ioctl call with an invalid baud_base value. This could cause a divide by zero error, leading to a kernel crash and denial of service.

Mitigation

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.

Additional information

  • Bugzilla 2307866: kernel: serial: core: check uartclk for zero to avoid divide by zero
  • CWE-369: Divide By Zero
  • FAQ: Frequently asked questions about CVE-2024-43893

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

5.5

5.5

Attack Vector

Local

Local

Attack Complexity

Low

Low

Privileges Required

Low

Low

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Understanding the Weakness (CWE)

CWE-369

Availability

Technical Impact: DoS: Crash, Exit, or Restart

A Divide by Zero results in a crash.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

My product is listed as "Out of Support Scope". What does this mean?

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