Cyber Resilience

CVE-2025-0492

Memory Safety in Dlink Dir-823X Firmware 240126 … 240802

Public PoCMemory Safety
Published
15 January 2025
Modified
24 September 2025
Patch / advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.019 77th percentile
Risk Priority 48 floored blend · peak EPSS

Summary

CVE-2025-0492 is a high-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Dlink Dir-823X Firmware. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 23% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A null pointer dereference vulnerability, tracked as CVE-2025-0492 and assigned CWE-404 and CWE-476, affects the FUN_00412244 function in D-Link DIR-823X devices running firmware versions 240126 and 240802. The flaw is rated critical with a CVSS 4.0 score of 8.7 and can be triggered remotely by manipulating specific inputs to the affected function.

Remote unauthenticated attackers can exploit the issue over the network to induce a denial-of-service condition, resulting in high impact to availability while leaving confidentiality and integrity unaffected. Public disclosure of an exploit means the attack vector is already known and potentially usable by threat actors.

The referenced advisories and vulnerability databases, including entries on VulDB and a detailed Notion report, point to D-Link’s site for vendor information, though no specific patch or mitigation steps are detailed in the available references. The EPSS score has remained low, with a current value of 0.0086 and a peak of 0.0170.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability has been found in D-Link DIR-823X 240126/240802 and classified as critical. Affected by this vulnerability is the function FUN_00412244. The manipulation leads to null pointer dereference. The attack can be launched remotely. The exploit has been disclosed to…

more

the public and may be used.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-1103Same product: Dlink Dir-823X
CVE-2025-29635Same product: Dlink Dir-823X
CVE-2025-2717Same product: Dlink Dir-823X
CVE-2025-29039Same product: Dlink Dir-823X
CVE-2024-39962Same product: Dlink Dir-823X
CVE-2025-29042Same product: Dlink Dir-823X
CVE-2025-29040Same product: Dlink Dir-823X
CVE-2025-29041Same product: Dlink Dir-823X
CVE-2025-29043Same product: Dlink Dir-823X
CVE-2025-8175Same vendor: Dlink

Affected Assets

dlink
dir-823x firmware
240126, 240802

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect resource releases after code is written.

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

Engineering principles can require explicit resource acquisition/release patterns that stop improper shutdown from being introduced.

Priority-based resource allocation limits the blast radius when released resources are not returned to the pool.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards for correct resource allocation and release.

DE.CM-09 partial match
prevents

Runtime monitoring can detect resource exhaustion caused by improper shutdown or release.

ID.AM-08 partial match
prevents

Lifecycle management of assets can encompass proper resource release at end-of-life or shutdown.

PR.IR-04 partial match
prevents

Capacity management helps surface leaks from unreleased resources but does not prevent the coding flaw.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect NULL dereference defects before release.

prevents

Including restart, recovery and media-handling instructions reduces the likelihood that resources or sensitive data will be left in an exposed or improperly released state after a failure.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References