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CVE-2024-20331· NVD / CVE Program· CNA cisco

Cisco Adaptive Security Appliance and Firepower Threat Defense Software VPN Authentication DoS Vulnerability

Noroxi assessment

Priority: Monitor (action score 23/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.67% (FIRST EPSS); higher than 50.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • According to the record, no fixed version is available yet.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

A vulnerability in the session authentication functionality of the Remote Access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to prevent users from authenticating. This vulnerability is due to insufficient entropy in the authentication process. An attacker could exploit this vulnerability by determining the handle of an authenticating user and using it to terminate their authentication session. A successful exploit could allow the attacker to force a user to restart the authentication process, preventing a legitimate user from establishing remote access VPN sessions.

MediumCVSS 5.9 · v3.1—No exploit No fix recorded
Published
Oct 23, 2024
Updated
Aug 11, 2026
EPSS
0.7% · 51th percentile

Report tools

JSON

Action score

23

Monitor

Low priority for now.

CVSS
23 / 40 · 5.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.9
CNA · cisco
6.8
0.9 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-20331

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
ciscoadaptive security appliance software
ciscosecure firewall threat defense

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • cisco adaptive security appliance software9.12.1
  • cisco adaptive security appliance software9.12.1.2
  • cisco adaptive security appliance software9.12.1.3
  • cisco adaptive security appliance software9.12.2
  • cisco adaptive security appliance software9.12.2.1
  • cisco adaptive security appliance software9.12.2.4
  • cisco adaptive security appliance software9.12.2.5
  • cisco adaptive security appliance software9.12.2.9
  • cisco adaptive security appliance software9.12.3
  • cisco adaptive security appliance software9.12.3.12
  • cisco adaptive security appliance software9.12.3.2
  • cisco adaptive security appliance software9.12.3.7
  • cisco adaptive security appliance software9.12.3.9
  • cisco adaptive security appliance software9.12.4
  • cisco adaptive security appliance software9.12.4.10
  • cisco adaptive security appliance software9.12.4.13
  • cisco adaptive security appliance software9.12.4.18
  • cisco adaptive security appliance software9.12.4.2
  • cisco adaptive security appliance software9.12.4.24
  • cisco adaptive security appliance software9.12.4.26

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

  • Cisco Cisco Adaptive Security Appliance (ASA) Software

    • 9.12.3, 9.8.3, 9.12.1, 9.8.1, 9.12.2, 9.8.2.45, 9.8.2, 9.8.4, 9.14.1, 9.12.4, 9.8.2.26, 9.8.2.24 … (+28)affected

  • Cisco Cisco Firepower Threat Defense Software

    • 6.2.3.14, 6.4.0.1, 6.2.3.7, 6.2.3, 6.4.0.2, 6.2.3.9, 6.2.3.1, 6.2.3.2, 6.4.0.5, 6.2.3.10, 6.4.0, 6.4.0.3 … (+28)affected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-20362Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTKEV
    90Now
  • CVE-2025-20333A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat DKEV
    90Now
  • CVE-2020-3452Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Read-Only Path Traversal VulnerabilityKEV
    90Now
  • CVE-2018-0296A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to causeKEV
    90Now
  • CVE-2024-20353A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat DefensKEV
    85Now
  • CVE-2023-20269A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTDKEV
    74This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-20101497 days apartA vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an un
    34Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-330 · Use of Insufficiently Random Values

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records