Threats / D-Link / CVE-2020-29557
CVE-2020-29557
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
D-Link DIR-825 R1 Devices vulnerability
D-Link DIR-825 R1 devices contain a buffer overflow vulnerability in the web interface that may allow remote code execution.
Verdict
Today item — known-exploited.
A buffer overflow in the web interface of D-Link DIR-825 R1 devices enables unauthenticated remote code execution. The vulnerability is actively exploited in the wild with high exploit probability.
CISA KEV Yes · 2021-11-034EPSS 0.5432 (verify live)5CVSS 9.8 (CISA)3CISA SSVC Exploitation: active · Automatable: yes · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
37 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
Probability (EPSS)
EPSS 0.5432 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: D-Link, DIR-825 R1 Devices. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 278 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious HTTP request to the web interface that exceeds buffer boundaries.
Business
The device becomes a compromised network access point under attacker control.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I inject shellcode through the overflow to execute arbitrary commands on the device.
Business
Attackers gain persistent presence on the network perimeter with administrative privileges.
3
Lateral reach — past segmentation narrative 3
Attacker
I use the compromised router to intercept, modify, or redirect network traffic.
Business
Customer data and credentials transmitted across the network are exposed to interception and theft.
4
Data at risk — exfiltration narrative 4
Attacker
I establish the device as a pivot point to attack internal network resources.
Business
Internal systems and sensitive assets become accessible to lateral movement attacks.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05