basicsecurity.net
Proof, not just disclosure.
Threats / Cisco / CVE-2018-0296
CVE-2018-0296 · EUVD no mirror located · GCVE no mirror located Verified 2026-08-04

Cisco Adaptive Security Appliance (ASA) vulnerability

Cisco ASA contains an improper input validation vulnerability in HTTP URL handling that could allow attackers to cause denial-of-service or information disclosure.

Verdict

Today item — known-exploited.

An attacker can exploit improper input validation of HTTP URLs in Cisco ASA to trigger denial-of-service conditions or leak sensitive information. This vulnerability is actively exploited in the wild with high exploitability.

CISA KEV Yes · 2021-11-035EPSS 0.99903 (verify live)6Exploit Weaponized · public PoC7CVSS 7.5 (CISA)4CISA SSVC Exploitation: active · Automatable: yes · Impact: partial4
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
395 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).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.99903 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) · Affected: Cisco, Adaptive Security Appliance (ASA). 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-20 Improper Input Validation.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: partialCISA'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 1245 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.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02

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.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I craft malformed HTTP URLs to bypass input validation checks in the ASA.
Business
The organization loses availability or confidentiality of security appliance functions.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I send specially crafted requests that cause the ASA to crash or become unresponsive.
Business
Network traffic inspection and security policy enforcement are disrupted, exposing the organization to unfiltered threats.
3

Lateral reach — past segmentation narrative 3

Attacker
I extract sensitive information through the validation bypass to reconnaissance the security posture.
Business
Attackers gain intelligence to plan further intrusions or lateral movement within the network.
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

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 395 reported-exploitation source(s)
  • CVSS 7.5 — CISA-assigned (CVE.org ADP)
  • CISA SSVC triage disposition (CVE.org ADP)
  • CWE weakness mapping — CNA-assigned (CVE.org)
  • Public exploit availability
  • 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/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by ciscoCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.