Cyber Resilience

CVE-2025-5622

CriticalPublic PoC

Published: 05 June 2025

Published
05 June 2025
Modified
06 June 2025
KEV Added
Patch
CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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 0.0109 78.3th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-5622 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Dir-816 Firmware. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 21.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

A vulnerability classified as critical was identified in the D-Link DIR-816 1.10CNB05 router. It resides in the wirelessApcli_5g function of the /goform/wirelessApcli_5g endpoint, where improper handling of the apcli_mode_5g, apcli_enc_5g, and apcli_default_key_5g arguments triggers a stack-based buffer overflow. The issue maps to CWE-119, CWE-121, and CWE-787 and carries a CVSS 4.0 score of 9.3 reflecting network-accessible attack conditions without authentication or user interaction.

An unauthenticated remote attacker can supply crafted input to the affected form handler and execute arbitrary code or crash the device, resulting in full compromise of confidentiality, integrity, and availability. Public exploit code has already been released, and the flaw is restricted to an end-of-life product line that receives no further vendor support.

The listed references point to a detailed proof-of-concept on GitHub, multiple VulDB entries, and the vendor’s site, but contain no remediation guidance or patches because the hardware is unsupported. The associated EPSS score has remained flat at 0.0109 with no material rise since disclosure.

EU & UK References

Vulnerability details

A vulnerability was found in D-Link DIR-816 1.10CNB05 and classified as critical. Affected by this issue is the function wirelessApcli_5g of the file /goform/wirelessApcli_5g. The manipulation of the argument apcli_mode_5g/apcli_enc_5g/apcli_default_key_5g leads to stack-based buffer overflow. The attack may be launched…

more

remotely. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
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.
Why these techniques?

Unauthenticated remote stack-based buffer overflow in the router's web CGI endpoint (/goform/wirelessApcli_5g) enables exploitation of public-facing web applications (T1190), exploitation of remote services (T1210), and DoS via application exploitation (T1499.004).

Affected Assets

dlink
dir-816 firmware
1.10cnb05

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119 CWE-787

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References