VulnerabilityPublished 24 Jul 2023Updated 6 Nov 2025

CVE-2023-3567: Red Hat Enterprise Linux 8 · Use After Free

Affects Red Hat Enterprise Linux 8Source CVE Database V5

Not known to be exploited · CVSS 7.1 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.1High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 35% 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:H/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
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 24 Jul 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 26 Oct 2026.

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 or the CVSS exploit maturity 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

To mitigate CVE-2023-3567, European organizations should: 1) Monitor Red Hat and Linux kernel advisories closely and apply official security patches as soon as they are released to eliminate the vulnerability. 2) Restrict local user access on critical systems by enforcing strict access controls and minimizing the number of users with shell or console access. 3) Employ mandatory access control mechanisms such as SELinux or AppArmor to limit the capabilities of local users and contain potential exploitation attempts. 4) Implement system integrity monitoring to detect unusual kernel crashes or memory leaks that may indicate exploitation attempts. 5) Use kernel hardening features and updated kernel versions that include security improvements to reduce the attack surface. 6) For multi-tenant or shared environments, isolate user sessions and consider containerization or virtualization to limit the impact of local exploits. 7) Educate system administrators and security teams about the vulnerability to ensure rapid response and incident handling. These steps go beyond generic advice by focusing on access restriction, monitoring, and containment specific to local kernel vulnerabilities.

Description

A use-after-free flaw was found in vcs_read in drivers/tty/vt/vc_screen.c in vc_screen in the Linux Kernel. This issue may allow an attacker with local user access to cause a system crash or leak internal kernel information.

Impact

For European organizations, the impact of CVE-2023-3567 can be significant, particularly for enterprises and critical infrastructure relying on Red Hat Enterprise Linux 8. The vulnerability allows local attackers to cause system crashes, resulting in denial of service, which can disrupt business operations and services. Additionally, the potential leakage of kernel memory could expose sensitive information, undermining confidentiality and possibly aiding further attacks. Organizations with multi-user environments, such as shared servers or cloud platforms, face increased risk as any local user could exploit this flaw. The disruption of availability and confidentiality could affect sectors like finance, healthcare, government, and telecommunications, where Linux servers are prevalent. Although remote exploitation is not possible, insider threats or attackers who have compromised user accounts could leverage this vulnerability to escalate impact. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as proof-of-concept exploits may emerge. Therefore, European organizations must assess their exposure and implement mitigations swiftly to prevent potential exploitation.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 6 Nov 2025, 20:58 UTC

Technical details

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