Page generated: 11 Nov 2026, 07:22 UTC
← Dashboard

CVE-2021-27137

An issue was discovered in router/upnp/src/ssdp.c in DD-WRT before 45724. An unsafe strcpy in the UPnP handling functionality allows an unauthenticated remote attacker to send a request that would overflow an internal fixed buffer. Exploitation requires the DD-WRT user to enable …

Read full description
An issue was discovered in router/upnp/src/ssdp.c in DD-WRT before 45724. An unsafe strcpy in the UPnP handling functionality allows an unauthenticated remote attacker to send a request that would overflow an internal fixed buffer. Exploitation requires the DD-WRT user to enable UPnP (which is off by default, and only listens on internal interfaces by default). This occurs in ssdp_msearch (reachable by an M-SEARCH request).
CVSS 8.1 (HIGH) KEV: KNOWN CATALOG

Attention and evidence

HYPE SCORE
0.0/10
REALITY · THREAT PRIORITY
8.2/10
General review priority; not probability

Evidence confidence: Exploitation recorded

Why this priority?
  • Recorded exploitation baseline: +7.00
  • Technical severity: CVSS 8.1: +1.21
  • Fresh EPSS: 4.00%: +0.02

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Sources: 8 documents and public datasets.

Hype components

Headline sample (25%)
0/100
Press, 30 days (60%)
0/100
Grounded branding (15%)
0/100
HYPE TOTAL0/100

Sources and documents

Recorded Future
Press · 07 Aug 2026, 07:00 · July 2026 CVE Landscape - Recorded Future
The Hacker News
Press · 22 Jul 2026, 07:00 · Hackers Exploit Windmill Flaw to Read Arbitrary Server Files Without Authentication - The Hacker News
Recorded Future
Press · 10 Jul 2026, 07:00 · June 2026 CVE Landscape - Recorded Future
Security Affairs
Press · 08 Jun 2026, 07:00 · IoT Botnet C0XMO Adds Competitor-Killing Capability - Security Affairs
The Hacker News
Press · 08 Jun 2026, 07:00 · ⚡ Weekly Recap: Instagram Account Hacks, Android Zero-Day, GitHub Worm and More - The Hacker News
See all 8 source documents
Korben
Press · 07 Jun 2026, 07:00 · C0XMO - the botnet squatting your old DD-WRT routers - Korben
BleepingComputer
Press · 07 Jun 2026, 07:00 · C0XMO botnet spreads via DD-WRT router flaw, kills rival malware - BleepingComputer
SOC Prime
Press · 05 Jun 2026, 07:00 · C0XMO Gafgyt Variant Spreads Through DD-WRT Routers - SOC Prime

Score evolution

● Hype   ● Reality

Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.

First record: hype 0.0 · reality 8.2 (2026-11-02 15:12). The curve appears once the score changes.

Public exploit evidence

0

Public exploit entries / repo candidates

Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.

Evidence in context

Confidence in exploitation evidence
Exploitation recorded
Priority basis
Recorded exploitation; CVSS 8.1; EPSS 4.0%
Attention, last 30 days
0 distinct story titles; 0 press documents; 0 publisher domains.
Technical potential
network access, no prior privileges, no user interaction, additional attack conditions.
Observed activity
Exploitation recorded in CISA KEV.
Known scale
Not quantified.
Evidence confidence basis
Trusted exploitation confirmation

Score evaluated: 2026-11-05 13:58:25.853394+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline
First press mention
05 Jun 2026, 07:00
Published
16 Jul 2026, 00:00
Added to the CISA KEV catalog
21 Jul 2026, 00:00
Latest press mention
07 Aug 2026, 07:00
Score calculated
05 Nov 2026, 13:58