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Threats / Cisco / CVE-2020-3259
CVE-2020-3259 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Cisco Adaptive Security Appliance (ASA) and Firepower Threat vulnerability

Cisco ASA and FTD contain an information disclosure vulnerability in web services interface URL parsing that could expose memory contents and confidential information.

Verdict

Today item, not a backlog item.

An attacker exploiting this buffer tracking flaw in invalid URL handling can retrieve sensitive data from affected devices running specific AnyConnect and WebVPN configurations, leading to information disclosure.

CISA KEV Yes · 2024-02-153Ransomware use Flagged3EPSS 0.71789 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
64 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 2024-02-15), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.71789 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-200 Information Exposure — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-200 · Information ExposureAuthorization / access control
02

Who’s exploiting it?

— attribution turns risk into urgency
Akira Ransomware

The #StopRansomware joint advisory AA24-109A reports that Akira ransomware affiliates gain initial access through Cisco VPN appliances lacking MFA, naming the group and the Cisco ASA/FTD CVEs they exploit to do so.11

03

Why it matters

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

Front door — unauthenticated access narrative 1

Attacker
I craft malformed URLs targeting the web services interface of vulnerable ASA or FTD devices.
Business
Confidential information stored in device memory becomes accessible to unauthorized parties.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I parse the returned memory contents to extract sensitive credentials, configuration data, or other protected information.
Business
Compromised credentials enable lateral movement and further network infiltration.
3

Lateral reach — past segmentation narrative 3

Attacker
I leverage disclosed information to establish persistent access or escalate privileges within the target environment.
Business
Security perimeter is breached, enabling ransomware deployment or data exfiltration campaigns.
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)
  • Ransomware-use flag (CISA)
  • EPSS probability (FIRST)
  • 64 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • 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.