CVE-2023-4459VulnerabilityPublished 21 Aug 2023Updated 15 Nov 2025

CVE-2023-4459: Red Hat Enterprise Linux 8.2 Advanced Update Support · NULL Pointer Dereference

Affects Red Hat Enterprise Linux 8.2 Advanced Update SupportSource CVE Database V5

Not known to be exploited · CVSS 5.5 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Aug 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

European organizations should implement the following specific mitigations: 1) Monitor Red Hat advisories closely and apply vendor patches promptly once available to address the NULL pointer dereference in vmxnet3. 2) Restrict local user access to systems running Red Hat Enterprise Linux 8.2 with vmxnet3 drivers, enforcing the principle of least privilege and using strong access controls to limit potential attackers. 3) Employ kernel crash monitoring and alerting tools to detect early signs of exploitation attempts or system instability related to vmxnet3. 4) In virtualized environments, consider isolating critical workloads and applying network segmentation to reduce the impact of potential DoS attacks. 5) Conduct regular vulnerability scans and penetration tests focusing on local privilege abuse scenarios to identify and remediate exposure. 6) Educate system administrators and security teams about this vulnerability and the importance of timely patch management. 7) If patching is delayed, consider temporary workarounds such as disabling or limiting the use of the vmxnet3 driver where feasible, or migrating affected workloads to alternative network drivers or kernel versions not impacted by this flaw.

Description

A NULL pointer dereference flaw was found in vmxnet3_rq_cleanup in drivers/net/vmxnet3/vmxnet3_drv.c in the networking sub-component in vmxnet3 in the Linux Kernel. This issue may allow a local attacker with normal user privilege to cause a denial of service due to a missing sanity check during cleanup.

Impact

For European organizations, this vulnerability primarily threatens system availability by enabling local attackers to cause kernel crashes and denial of service conditions. Organizations running Red Hat Enterprise Linux 8.2 in virtualized environments using the vmxnet3 driver—common in data centers and cloud infrastructures—may experience service interruptions, impacting business continuity and operational reliability. Critical sectors such as finance, healthcare, telecommunications, and government services that rely on stable virtualized Linux environments could face operational disruptions. While the vulnerability does not expose sensitive data or allow privilege escalation, the resulting downtime could lead to indirect financial losses, reputational damage, and regulatory compliance challenges, especially under stringent European data protection and operational resilience frameworks. The requirement for local access limits remote exploitation risks but does not eliminate insider threats or risks from compromised user accounts.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 15 Nov 2025, 09:18 UTC

Technical details

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