CVE-2023-39197VulnerabilityPublished 23 Jan 2024Updated 20 Nov 2025

CVE-2023-39197: Red Hat Enterprise Linux 6 · Out-of-bounds Read

Affects Red Hat Enterprise Linux 6Source CVE Database V5

Not known to be exploited · CVSS 4.0 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.0Medium

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 61% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: None
Availability: None

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within 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 23 Jan 2024
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-2023-39197, European organizations should: 1) Apply the latest security patches and kernel updates provided by Red Hat for Enterprise Linux 6 to address the vulnerability directly. 2) If patching is not immediately feasible, disable or restrict the use of the DCCP protocol at the firewall or kernel level to prevent exploitation via crafted packets. 3) Employ network segmentation and limit exposure of vulnerable systems to untrusted networks, especially blocking DCCP traffic from external sources. 4) Monitor network traffic for unusual DCCP activity or malformed packets that could indicate exploitation attempts. 5) Review and update intrusion detection and prevention systems (IDS/IPS) signatures to detect potential exploitation patterns related to this vulnerability. 6) Consider upgrading legacy systems to supported Red Hat Enterprise Linux versions with active security maintenance to reduce exposure to similar vulnerabilities. 7) Conduct regular security audits and vulnerability assessments focusing on legacy kernel components and network protocol usage.

Description

An out-of-bounds read vulnerability was found in Netfilter Connection Tracking (conntrack) in the Linux kernel. This flaw allows a remote user to disclose sensitive information via the DCCP protocol.

Impact

For European organizations, the primary impact of CVE-2023-39197 is the potential leakage of sensitive kernel memory information, which could be leveraged by attackers to gain further insights into system internals or to facilitate subsequent attacks. Although the vulnerability does not directly allow system compromise or denial of service, the confidentiality breach could be critical in high-security environments such as government, finance, or critical infrastructure sectors. Organizations relying on Red Hat Enterprise Linux 6, especially those exposing DCCP traffic or operating in untrusted network environments, face increased risk. The medium severity rating and high attack complexity reduce the immediate threat level, but the presence of legacy systems in European enterprises means that some environments may remain vulnerable. The vulnerability could also affect compliance with data protection regulations if sensitive information is disclosed. Additionally, the lack of known exploits reduces the urgency but does not eliminate the risk, as attackers could develop exploits in the future.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 20 Nov 2025, 20:44 UTC

Technical details

References

Community reviews

Related threats