Threats / Cisco / CVE-2018-0151

CVE-2018-0151 · EUVD no mirror located · GCVE no mirror located Verified 2026-09-19

Cisco IOS and XE Software vulnerability

A buffer overflow vulnerability in the QoS subsystem of Cisco IOS and IOS XE Software allows unauthenticated remote attackers to cause denial of service or execute arbitrary code with elevated privileges.

Verdict

Today item — known-exploited.

This vulnerability poses significant risk to Cisco router and switch deployments. Unauthenticated remote exploitation enables attackers to disrupt network operations or gain administrative control without requiring valid credentials or prior system access.

CISA KEV Yes · 2022-03-03⁵EPSS 0.14197 (verify live)⁶CVSS 9.8 (CISA)⁴CISA SSVC Exploitation: active · Automatable: yes · Impact: total⁴

Is it exploitable?

— the evidence, ranked above the score

Reported exploitation

1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.

cisa.gov ↗Confirmed

Exploited in the wild

Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03).

CISA KEV ↗Confirmed

Probability (EPSS)

EPSS 0.14197 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.

FIRST EPSS ↗High

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: Cisco, IOS and IOS XE Software. 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.

CISA-ADP ↗Reported

Weakness (CWE)

Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.

CVE.org ↗Reported

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.

CISA-ADP ↗Reported

Currency of the record

CISA added this to its KEV catalog 1436 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.

CISA KEV ↗CVE.org ↗Reported

WeaknessCWE-119 · Memory Buffer Bounds ErrorMemory safety

Who’s exploiting it?

— attribution turns risk into urgency

Attribution 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.

Why it matters

— the attack path, told twice: adversary, then board

Front door — unauthenticated access narrative 1

Attacker

I craft a malicious packet targeting the QoS subsystem to trigger a buffer overflow condition.

Business

Network infrastructure becomes unstable or completely unavailable, disrupting all dependent business operations.

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker

I send the crafted packet remotely without authentication to a vulnerable device on the network.

Business

Attackers bypass security perimeters and gain direct influence over critical routing and switching infrastructure.

Lateral reach — past segmentation narrative 3

Attacker

I execute arbitrary code with elevated privileges on the compromised device.

Business

Attackers establish persistent control, intercept traffic, redirect communications, or pivot to internal network segments.

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.

Coverage & confidence

— what we know, and what we don’t

Established (cited)

KEV listing (CISA)

EPSS probability (FIRST)

1 reported-exploitation source(s)

CVSS 9.8 — CISA-assigned (CVE.org ADP)

CISA SSVC triage disposition (CVE.org ADP)

CWE weakness mapping — CNA-assigned (CVE.org)

Catalogued by cisco (CNA)

Coverage gaps — stated, not hidden

No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.

EPSS & exposure are time-varying; verify live at the source.

Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.

No finder is named in the public CVE record or the scanned vendor advisory — attribution scoped to the sources checked.

Disclosure & credit²

Catalogued by ciscoCNA

Credited with finding itNo finder is named in the public CVE record or the scanned vendor advisory — attribution scoped to the sources checked.

Found an error? Propose a correction.

A correction is a cited counter-claim — it must cite a source, gets reviewed by a second human, and is never auto-applied. See the correction convention and our identity npub1j7gt9ky7sfcrjn8jjee6693dkzvk4rahs0fk2suu7968dfns62zs3mqm3y.

With JavaScript off: publish a signed kind 1111 Nostr event tagging ["r", "https://basicsecurity.net/threat/cve-2018-0151.html"], ["v", "sha256:2c60d7c97839f92d49c290140dc9a4d3625a3cb026677beca24a0ca58dbb5c20"] (the record version), plus ["src", "<your source URL>"] and ["t", "correction"], per the correction convention. Our identity: npub1j7gt9ky7sfcrjn8jjee6693dkzvk4rahs0fk2suu7968dfns62zs3mqm3y. Cite-or-die: an event with no src is a coverage finding, not a proposal.