CVE-2024-43168VulnerabilityPublished 8 Aug 2024Updated 3 Nov 2025

CVE-2024-43168: Red Hat Enterprise Linux 6 · Heap-based Buffer Overflow

Affects Red Hat Enterprise Linux 6Source CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.8Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: 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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 8 Aug 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

Organizations should first verify if they are running Red Hat Enterprise Linux 6 with the affected Unbound component. Since this is a legacy OS, consider upgrading to a supported Red Hat Enterprise Linux version where this issue is resolved. If upgrading is not immediately feasible, apply any patches or updates provided by Red Hat addressing this CVE. In the absence of patches, restrict local access to trusted users only and monitor for unusual activity or crashes related to Unbound. Implement strict user privilege management to minimize the risk of local exploitation. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts. Regularly review Red Hat security advisories and NLnet Labs communications for updates or clarifications. Finally, consider isolating critical DNS resolver services or using alternative DNS resolver implementations that do not exhibit this vulnerability.

Description

DISPUTE NOTE: this issue does not pose a security risk as it (according to analysis by the original software developer, NLnet Labs) falls within the expected functionality and security controls of the application. Red Hat has made a claim that there is a security risk within Red Hat products. NLnet Labs has no further information about the claim, and suggests that affected Red Hat customers refer to available Red Hat documentation or support channels. ORIGINAL DESCRIPTION: A heap-buffer-overflow flaw was found in the cfg_mark_ports function within Unbound's config_file.c, which can lead to memory corruption. This issue could allow an attacker with local access to provide specially crafted input, potentially causing the application to crash or allowing arbitrary code execution. This could result in a denial of service or unauthorized actions on the system.

Impact

The potential impact of CVE-2024-43168 includes denial of service through application crashes and the possibility of arbitrary code execution, which could lead to unauthorized actions on affected systems. Since exploitation requires local access and user interaction, remote attackers cannot directly exploit this vulnerability without first gaining local access. The impact on confidentiality, integrity, and availability is moderate due to the medium CVSS score and the limited scope of affected systems (Red Hat Enterprise Linux 6 with Unbound). Organizations running legacy Red Hat Enterprise Linux 6 systems, especially those using Unbound for DNS resolution, may face service disruptions or compromise if exploited. This could affect internal network services, DNS resolution reliability, and potentially allow privilege escalation or lateral movement if arbitrary code execution is achieved. However, the lack of known exploits in the wild and the dispute over the security risk reduce the immediate threat level. Still, the presence of this vulnerability in critical infrastructure or enterprise environments could pose operational risks and require mitigation.

Summary

CVE-2024-43168 is a heap-based buffer overflow vulnerability identified in the cfg_mark_ports function within the config_file.c source file of the Unbound DNS resolver component bundled with Red Hat Enterprise Linux 6. The vulnerability arises when specially crafted input is processed, leading to memory corruption on the heap. This corruption can cause the Unbound process to crash (denial of service) or potentially allow an attacker to execute arbitrary code with the privileges of the Unbound process. Exploitation requires local access to the system, low attack complexity, and user interaction, with the attacker needing at least local privileges. The vulnerability was reported by Red Hat, but NLnet Labs, the original developer of Unbound, disputes the security risk, stating the behavior falls within expected functionality and security controls. Despite this dispute, Red Hat has published the CVE with a CVSS v3.1 score of 4.8, indicating a medium severity level. No public exploits or active exploitation have been reported. The affected product is Red Hat Enterprise Linux 6, a legacy operating system version that is still in use in some environments. The vulnerability highlights the risk of heap-based buffer overflows in DNS resolver components, which are critical for network operations and security.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 28 Feb 2026, 06:26 UTC

Technical details

References

Community reviews

Related threats