CVE-2023-39193VulnerabilityPublished 9 Oct 2023Updated 6 Nov 2025

CVE-2023-39193: Red Hat Enterprise Linux 8 · Out-of-bounds Read

Affects Red Hat Enterprise Linux 8Source CVE Database V5

Not known to be exploited · CVSS 6.1 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 36% 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:L

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

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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Oct 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

1. Apply official Red Hat kernel patches as soon as they become available to remediate the vulnerability in the Netfilter subsystem. 2. Restrict CAP_NET_ADMIN privileges strictly to trusted administrators and processes to minimize the risk of local exploitation. 3. Implement strict access controls and monitoring on systems running Red Hat Enterprise Linux 8 to detect unauthorized privilege escalations or suspicious activity. 4. Employ kernel integrity monitoring tools to detect abnormal crashes or memory access patterns indicative of exploitation attempts. 5. Use security frameworks such as SELinux or AppArmor to limit the capabilities of processes that require network administration privileges. 6. Regularly audit user accounts and service permissions to ensure no unnecessary CAP_NET_ADMIN rights are granted. 7. Educate system administrators about the risks of local privilege misuse and encourage prompt reporting of unusual system behavior. 8. Consider network segmentation and isolation for critical systems to reduce the impact of potential local exploits.

Description

A flaw was found in the Netfilter subsystem in the Linux kernel. The sctp_mt_check did not validate the flag_count field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.

Impact

For European organizations, this vulnerability could lead to denial of service conditions or leakage of sensitive kernel memory if exploited. Organizations relying on Red Hat Enterprise Linux 8 for critical infrastructure, cloud services, or enterprise applications may experience service disruptions or data exposure. Although exploitation requires local privileged access, insider threats or compromised accounts with CAP_NET_ADMIN capabilities could leverage this flaw to escalate impact. Confidentiality breaches could expose sensitive information residing in kernel memory, potentially aiding further attacks. The availability impact from kernel crashes could disrupt network filtering and firewall services, affecting business continuity. Given the widespread use of Red Hat Enterprise Linux 8 in European enterprises and public sector organizations, the vulnerability represents a moderate risk that must be addressed promptly to maintain system integrity and operational stability.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 6 Nov 2025, 20:57 UTC

Technical details

References

Community reviews

Related threats