VulnerabilityPublished 29 Feb 2024Updated 2 Aug 2024

CVE-2024-27661: Use of NullPointerException Catch to Detect NULL Pointer Dereference

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

6.5Medium

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

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

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
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: 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: None: There is no loss of confidentiality within the impacted component.
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 29 Feb 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 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

Monitor D-Link’s official support channels for firmware updates addressing CVE-2024-27661 and apply patches promptly once released.
Restrict access to the router’s management interfaces and network segments to trusted users only, using network segmentation and access control lists (ACLs).
Disable unnecessary services or features on the router that could be exploited to trigger the vulnerability.
Implement network monitoring to detect unusual traffic patterns or repeated malformed input attempts targeting the router.
Where possible, replace or upgrade affected devices with models that have received security updates or have better security track records.
Educate users about the risks of connecting untrusted devices to the local network to reduce the likelihood of internal exploitation.
Consider deploying intrusion detection/prevention systems (IDS/IPS) that can identify and block crafted packets designed to exploit this vulnerability.
Maintain regular backups of router configurations to enable quick recovery in case of service disruption.

Description

D-Link DIR-823G A1V1.0.2B05 was discovered to contain Null-pointer dereferences in sub_4484A8(). This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted input.

Impact

The primary impact of CVE-2024-27661 is a denial of service condition on affected D-Link DIR-823G routers, which can disrupt internet connectivity and network services for users relying on these devices. For organizations, this can lead to loss of productivity, interrupted communications, and potential operational delays, especially in small offices or home office environments where this router is commonly deployed. Although the vulnerability does not expose sensitive data or allow unauthorized access, the loss of availability can indirectly affect business continuity and user trust. In scenarios where these routers serve as gateways or critical network infrastructure, the DoS could also impact connected IoT devices or security monitoring systems. The lack of authentication or user interaction requirements lowers the barrier for attackers within the local network to exploit this flaw, increasing the risk in environments with less controlled network access. Since no known exploits are currently reported, the immediate threat level is moderate, but the potential for future exploitation remains if patches are not applied promptly once available.

CWE-395Use of NullPointerException Catch to Detect NULL Pointer Dereference (opens in a new tab)
Base weakness
Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.
Architecture and Design · Implementation
Do not extensively rely on catching exceptions (especially for validating user input) to handle errors. Handling exceptions can decrease the performance of an application.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

calm-healer-839.notion.site/D-LINK-DIR-823G-NPD-0x42444C-34458f12482346b291f334eea12e6fd0?pvs=4 (opens in a new tab)

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 28 Feb 2026, 10:13 UTC

WeaknessesCWE-395

Technical details

References

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