Uncontrolled resource consumption in Cisco Adaptive Security Appliance Software
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
A vulnerability in the SSH server of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition for the SSH server of an affected device. This vulnerability is due to a logic error when an SSH session is established. An attacker could exploit this vulnerability by sending crafted SSH messages to an affected device. A successful exploit could allow the attacker to exhaust available SSH resources on the affected device so that new SSH connections to the device are denied, resulting in a DoS condition. Existing SSH connections to the device would continue to function normally. The device must be rebooted manually to recover. However, user traffic would not be impacted and could be managed using a remote application such as Cisco Adaptive Security Device Manager (ASDM).
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | 9.16.4.67; 9.16.4.70; 9.18.4.40; 9.20.3 | — | No fix listed | CNA |
- Cisco Adaptive Security Appliance (ASA) Software VendorCisco Affected 9.16.4.67; 9.16.4.70; 9.18.4.40; 9.20.3 Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.67:*:*:*:*:*:*:* | 9.16.4.67 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.70:*:*:*:*:*:*:* | 9.16.4.70 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.4.40:*:*:*:*:*:*:* | 9.18.4.40 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.20.3:*:*:*:*:*:*:* | 9.20.3 | Vulnerable | Cisco |
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.67:*:*:*:*:*:*:* Versions 9.16.4.67 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.70:*:*:*:*:*:*:* Versions 9.16.4.70 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.4.40:*:*:*:*:*:*:* Versions 9.18.4.40 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.20.3:*:*:*:*:*:*:* Versions 9.20.3 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2024-20526
- 2026-10-03 Alias added: GHSA-vq87-vqwh-6mj9
References
Advisory 1
More Cisco Adaptive Security Appliance Software vulnerabilities
- TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
- TI-2016-05454 Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on… KEVCVSS 3.1HIGH 8.8
- TI-2023-06973 Authentication bypass in Cisco Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.1
- TI-2026-82192 Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN KEVCVSS 3.1HIGH 8.6
- TI-2026-16533 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense… KEVCVSS 3.1HIGH 8.6
- TI-2025-14657 Missing authorization in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
Sources
- CVE-2024-20526 · CVE Program
- CVE-2024-20526 · NVD
- FIRST EPSS
- GHSA-vq87-vqwh-6mj9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences