CVE-2017-3807 Memory corruption in Cisco ASA Software with Clientless SSL VPN portal is enabled Major Releases 9.0-9.6
Authenticated remote attackers can trigger a heap overflow in Cisco ASA Clientless SSL VPN via crafted URLs, potentially causing system reloads or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2017-3807?
CVE-2017-3807 is a high-severity memory corruption vulnerability in Cisco Adaptive Security Appliance Software, published on 9 Feb 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A vulnerability in Common Internet Filesystem (CIFS) code in the Clientless SSL VPN functionality of Cisco ASA Software, Major Releases 9.0-9.6, could allow an authenticated, remote attacker to cause a heap overflow. The vulnerability is due to insufficient validation of user supplied input. An attacker could exploit this vulnerability by sending a crafted URL to the affected system. An exploit could allow the remote attacker to cause a reload of the affected system or potentially execute code. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed firewall mode only and in single or multiple context mode. This vulnerability can be triggered by IPv4 or IPv6 traffic. A valid TCP connection is needed to perform the attack. The attacker needs to have valid credentials to log in to the Clientless SSL VPN portal. Vulnerable Cisco ASA Software running on the following products may be affected by this vulnerability: Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA 5500-X Series Next-Generation Firewalls, Cisco Adaptive Security Virtual Appliance (ASAv), Cisco ASA for Firepower 9300 Series, Cisco ASA for Firepower 4100 Series. Cisco Bug IDs: CSCvc23838.
Weakness: CWE-119
Which versions are affected by CVE-2017-3807?
It affects 1 product.
Products include Cisco Adaptive Security Appliance Software.
How do I fix CVE-2017-3807?
No fix has been published for CVE-2017-3807 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2017-3807 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-3807 exists.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in Cisco Adaptive Security Appliance Software
- CVE-2025-20333 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow
- CVE-2016-6366 Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow
- CVE-2026-20349 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection
- CVE-2024-20353 Cisco ASA and FTD Denial of Service
- CVE-2016-6367 Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution
All Cisco Adaptive Security Appliance Software vulnerabilities
Sources
Also known as GHSA-77g6-4h48-g6wv.