InfoSecBulletin Cybersecurity for mankind
Cisco announced updates on Wednesday to fix a security flaw in its Adaptive Security Appliance (ASA) that is currently being exploited and could cause a denial-of-service (DoS) condition.
CVE-2024-20481 (CVSS score: 5.8) is A vulnerability in the Remote Access VPN (RAVPN) service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) of the RAVPN service.
Microsoft’s November 2026 Patch Tuesday addresses 1,093 flaws, with Outlook zero-day
Barracuda ESG flaws exploited, gaining root access
Apple, SAP, and Ivanti Patch Critical flaws Affecting Messaging, Bluetooth, and Enterprise Systems
Jailbroken DeepSeek AI Agent Conducts Two-Week Cyberattack on European Telecom
Daily Cyber security update for 10.11. 2026
IBM fixes 208 API Connect vulnerabilities, 47 critical
89 New ransomware groups emerge in 2026, claiming over 2,200 victims
Daily Cyber security update for 08.11. 2026
Japan banking crisis
Outage causes disruption at 128 japan banks: preventing ATM transaction
Daily Cyber security update for 06.11. 2026
This vulnerability stems from resource exhaustion. An attacker can exploit it by sending many VPN authentication requests to the device, potentially causing a denial of service (DoS) for the RAVPN service. In some cases, the device may need to be rebooted to restore the service. Other services unrelated to VPN are not affected.
“An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device,” Cisco said in an advisory. “A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device.”
Earlier this April, Cisco Talos reported an increase in brute-force attacks on VPN services, web application logins, and SSH services since March 18, 2024.
These attacks targeted various equipment from companies like Cisco, Check Point, Fortinet, SonicWall, MikroTik, Draytek, and Ubiquiti.
“The brute-forcing attempts use generic usernames and valid usernames for specific organizations,” Talos noted at the time. “These attacks all appear to be originating from TOR exit nodes and a range of other anonymizing tunnels and proxies.”
Cisco has also released patches to remediate three other critical flaws in FTD Software, Secure Firewall Management Center (FMC) Software, and Adaptive Security Appliance (ASA), respectively.
