CVE-2024-53123
Description
A flaw was found in the Linux kernel's Multipath TCP (MPTCP) implementation. Due to improper handling of racing socket disconnect events, the kernel fails to handle error returns appropriately, leading to a division-by-zero error during TCP window calculations. A local attacker can exploit this issue to trigger a system crash, resulting in a denial of service (DoS).
Mitigation
Disable Multipath TCP (MPTCP) protocol support if it is not required:
1. Temporarily disable MPTCP by running:
# sysctl -w net.mptcp.enabled=0
2. Persist the configuration across system reboots by creating a sysctl configuration file:
# echo "net.mptcp.enabled = 0" > /etc/sysctl.d/99-mptcp.conf
# sysctl -p /etc/sysctl.d/99-mptcp.conf
Caveats:
Disabling MPTCP will prevent applications from establishing MPTCP connections, causing them to fall back to standard TCP or fail if MPTCP is explicitly required. Applying this configuration takes effect immediately without requiring a system reboot. If unprivileged user namespaces are permitted, unprivileged users may still be able to create new network namespaces with MPTCP enabled.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert: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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | 5.5 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
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
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability
When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.
Confidentiality,Integrity
Technical Impact: Read Files or Directories; Read Application Data
When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).
Access Control
Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism
This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
Frequently Asked Questions
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