Cyber Resilience

CVE-2025-4883

HighPublic PoC

Published: 18 May 2025

Published
18 May 2025
Modified
21 May 2025
KEV Added
Patch
CVSS Score v4 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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 0.0122 79.5th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-4883 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Di-8100G Firmware. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 20.5% 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 stack-based buffer overflow vulnerability exists in the D-Link DI-8100 firmware version 16.07.26A1. The flaw resides in the ctxz_asp function within the /ctxz.asp file on the Connection Limit Page, where unsanitized values supplied to the def, defTcp, defUdp, defIcmp, and defOther parameters can overflow a stack buffer. The issue is tracked as CVE-2025-4883 and carries a CVSS 4.0 score of 8.6.

An authenticated remote attacker can send a crafted HTTP request to the affected endpoint and achieve arbitrary code execution or a denial-of-service condition on the device. Public proof-of-concept code has already been released, enabling any party with administrative credentials to the web interface to trigger the overflow.

The EPSS score remains flat at 0.0122 with no material increase since disclosure. No vendor advisory or firmware update addressing the flaw is referenced in the available sources.

EU & UK References

Vulnerability details

A vulnerability was found in D-Link DI-8100 16.07.26A1. It has been declared as critical. This vulnerability affects the function ctxz_asp of the file /ctxz.asp of the component Connection Limit Page. The manipulation of the argument def/defTcp/defUdp/defIcmp/defOther leads to stack-based buffer…

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overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.

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.
Why these techniques?

Stack-based buffer overflow in the router's public-facing web management interface (/ctxz.asp, ctxz_asp function) via manipulated parameters (def/defTcp/defUdp/defIcmp/defOther) enables remote code execution through exploitation of a public-facing application. Requires authentication but fits T1190 as a vulnerable internet-exposed service.

Affected Assets

dlink
di-8100g firmware
16.07.26a1

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