NVD / CVE Program· CNA cisco

CVE-2025-20263: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service Vulnerability

Noroxi assessment

Priority: Monitor (action score 34/100)

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 52% 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. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.

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

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability in the web services interface of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected system.  This vulnerability is due to insufficient boundary checks for specific data that is provided to the web services interface of an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected system. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could cause the system to reload, resulting in a denial of service (DoS) condition.

HighCVSS 8.6 · v3.1—No exploit No fix recorded

BDU:2025-10357

Published: Aug 14, 2025
Updated: Jun 17, 2026
EPSS: 0.6% · 52th percentile
CWE: CWE-680

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.6 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · cisco: 8.6; NVD has not scored this yet; the score shown is the CNA’s.

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.

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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.

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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-2025-20253Cisco IOS, IOS XE, Secure Firewall Adaptive Security Appliance, and Secure Firewall Threat Defense Software IKEv2 Denial of Service Vulnerability
34Monitor
CVE-2025-20251Cisco Secure Firewall Adaptive Security Appliance and Cisco Secure Firewall Threat Defense Software Authenticated Arbitrary File Deletion
34Monitor
CVE-2025-20243Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability
34Monitor

Published before and after this one in the same product

← EarlierCVE-2025-20244Aug 14, 2025 · Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access VPN Web Server Denial of Service Vulnerability
30Monitor
← EarlierCVE-2025-20252Aug 14, 2025 · A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software an
23Monitor
← EarlierCVE-2025-20254Aug 14, 2025 · A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software an
23Monitor

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.

No nightly-computed relations.

Chain candidates

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

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Bug bounty scope

No known public program.

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

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.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Changed
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-680 · Integer Overflow to Buffer Overflow

CVSS vector

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

nvd-secondary

Attack context

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

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

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

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-buffer-overflow-PyRUhWBC

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

All records