CVE-2026-20248 A vulnerability in the DNS over TCP implementation of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software…
Description
A vulnerability in the DNS over TCP implementation 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 the TCP DNS response handler to unexpectedly restart, causing the device to reload. This vulnerability is due to a logic error when parsing a DNS query and tracking the size of the incoming buffers. An attacker could exploit this vulnerability by formatting a crafted reply to a DNS query sent from the targeted device. A successful exploit could allow the attacker to cause the device to reload, causing a denial of service (DoS) condition. Note: The attacker must be able to respond to DNS queries from the device, either by controlling the DNS service or through a machine-in-the-middle attack.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.24 | 9.24.1 → 9.24.1.155 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.23 | 9.23.1 → 9.23.1.195 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.22 | 9.22.1.1 → 9.22.3.5 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.20 | 9.20.1 → 9.20.4.235 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19 | 9.19.1 → 9.19.1.42 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18 | 9.18.1 → 9.18.4.135 | No fix stated |
| Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16 | 9.16.1 → 9.16.4.92 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software | 10.0.0 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.7 | 7.7.0 → 7.7.11 | No fix stated |
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| Product | Affected versions | Fixed in |
|---|---|---|
| Cisco Secure Firewall Threat Defense (FTD) Software 7.6 | 7.6.0 → 7.6.4 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.4 | 7.4.0 → 7.4.7 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.3 | 7.3.0 → 7.3.1.2 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.2 | 7.2.0 → 7.2.11 | No fix stated |
| Cisco Secure Firewall Threat Defense (FTD) Software 7.0 | 7.0.0 → 7.0.9 | No fix stated |
References
- cisco-sa-asaftd-tcpdns-dos-p6dUnjr5 sec.cloudapps.cisco.com
Timeline
- Published
- Last modified