Vulnerabilidade em Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

Resumo

Foi divulgada uma vulnerabilidade em Cisco Secure Firewall Adaptive Security Appliance (ASA) Software. A gravidade é alta, com nota CVSS 8,6.

Há evidência de exploração ativa: a agência americana CISA incluiu a falha no catálogo KEV em 29 out 2026.

Versões afetadas

• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.1
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.1.28
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2.3
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2.7
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2.11
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2.13
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.2.14
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.3.3
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.3
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.16.3.14
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.18.1

Segundo o registro oficial do CVE. Confira a versão exata com o fabricante.

O que fazer

1. Verifique se a sua empresa usa Cisco Secure Firewall Adaptive Security Appliance (ASA) Software e em qual versão.
2. Aplique a atualização de segurança do fabricante (veja as referências abaixo).
3. Se não der para atualizar agora, reduza a exposição, por exemplo restringindo o acesso pela internet. Isso não substitui a correção.
4. Como a falha já está sendo explorada, procure sinais de comprometimento nos sistemas que ficaram expostos.

Linha do tempo das fontes

1. 29 out 2026 CISA KEVoficial Incluída no catálogo KEV: exploração ativa confirmada
2. 29 out 2026 SecurityWeekimprensa Attackers Exploit Second Cisco Firewall VPN Zero-Day Since August
3. 29 out 2026 The Hacker Newsimprensa Cisco Patches Actively Exploited ASA and FTD VPN Flaw That Can Crash Firewalls
4. 29 out 2026 BleepingComputerimprensa New Cisco firewall zero-day exploited to crash SSL VPN devices

Descrição oficial CVE.org, em inglês

A vulnerability in the Remote Access SSL VPN service 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 device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to logic errors when secondary authentication is configured on a tunnel group. An attacker could exploit this vulnerability by sending a crafted request when connecting to the SSL remote access VPN. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Referências

• CVE-2026-76418 no CVE.org
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tunnel-dos-s6mgkb75