CVE-2023-4273VulnerabilityPublished 9 Aug 2023Updated 14 Nov 2025

CVE-2023-4273: Red Hat Enterprise Linux 9 · Stack-based Buffer Overflow

Affects Red Hat Enterprise Linux 9Source CVE Database V5

Not known to be exploited · CVSS 6.0 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.0Medium

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 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

To mitigate CVE-2023-4273, European organizations should prioritize the following actions: 1) Apply official patches from Red Hat as soon as they are released to address the buffer overflow in the exFAT driver. 2) Restrict local privileged access strictly to trusted administrators and users to reduce the risk of exploitation by malicious insiders or compromised accounts. 3) Monitor systems for unusual kernel activity or crashes that could indicate attempted exploitation. 4) Implement strict access controls and auditing on systems running Red Hat Enterprise Linux 9, especially those handling sensitive data or critical workloads. 5) Limit or disable the use of exFAT filesystems where possible, or enforce strict validation of removable media to prevent malicious files from triggering the vulnerability. 6) Employ kernel hardening techniques such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) to reduce exploitation success. 7) Educate system administrators about the vulnerability and the importance of applying updates promptly. These targeted measures go beyond generic advice by focusing on controlling privileged access, filesystem usage, and proactive monitoring.

Description

CVE-2023-4273 is a stack-based buffer overflow vulnerability in the exFAT driver of the Linux kernel used by Red Hat Enterprise Linux 9. It arises from improper handling of file name reconstruction when merging file name parts into a single long file name, where characters are copied into a stack variable without adequate bounds checking. This flaw can be exploited by a local attacker with elevated privileges to overflow the kernel stack, potentially leading to privilege escalation and compromise of confidentiality and integrity. The vulnerability has a CVSS score of 6.0, indicating medium severity, and does not require user interaction but does require high privileges to exploit. No known exploits are currently reported in the wild. European organizations using Red Hat Enterprise Linux 9 are at risk, especially those with sensitive or critical workloads. Mitigation involves applying vendor patches once available and restricting local privileged access. Countries with significant Red Hat Enterprise Linux deployments and critical infrastructure are more likely to be affected.

Impact

For European organizations, the impact of CVE-2023-4273 can be significant, particularly in sectors relying on Red Hat Enterprise Linux 9 for critical infrastructure, servers, or workstations. A successful exploit could allow a local privileged attacker to escalate privileges further or execute arbitrary code within the kernel, undermining system integrity and confidentiality. This could lead to unauthorized access to sensitive data, disruption of services, or persistent compromise of affected systems. Organizations with multi-user environments or those that allow local privileged access to multiple users are at higher risk. The vulnerability does not directly enable remote exploitation, limiting its scope, but insider threats or attackers who have already gained some level of privileged access could leverage this flaw to deepen their control. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time. The impact is heightened in environments where exFAT filesystems are used extensively, such as for removable media or shared storage, increasing the attack surface.

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Description

AI analysisMachine-generated, updated 21 Nov 2025, 15:12 UTC

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